Statement Of Cash Flows [Abstract]
| Concept | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | 
|---|---|---|
| Statement of cash flows [abstract] | ||
| Cash flows from (used in) operating activities [abstract] | ||
| Adjustments for dividend income | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for finance income | 
                                                275,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                2 6 9
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Cash flows from (used in) operations before changes in working capital | 
                                                18 ,728
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                14, 245
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for decrease (increase) in trade and other receivables | 
                                                313,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                4,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for increase (decrease) in trade and other payables | 
                                                49,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                3,593,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for depreciation and amortisation expense and impairment loss (reversal of impairment loss) recognised in profit or loss | 
                                                5,3 86
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                5,6 16
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for depreciation expense | 
                                                3, 4 87
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                4,06 8
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for gain (loss) on disposals, property, plant and equipment | 
                                                26,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                59,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for gain (loss) on disposal of investments in subsidiaries, joint ventures and associates | 
                                                247,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Adjustments for undistributed profits of investments accounted for using equity method | 
                                                1 99
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Cash flows from (used in) investing activities [abstract] | ||
| Cash advances and loans made to related parties | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Cash receipts from repayment of advances and loans made to related parties | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Proceeds from disposal of non-current assets or disposal groups classified as held for sale and discontinued operations | 
                                                632,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                4 ,14 4
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Purchase of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets | 
                                                3 ,42 2
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                4, 573
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Cash flows from (used in) financing activities [abstract] | ||
| Cash advances and loans from related parties | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Cash repayments of advances and loans from related parties | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                —
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             |