Before the Renters' Rights Act, retaliatory eviction was a widespread concern. A tenant would report a leaking roof or a damp and mould problem, and the landlord would respond by serving a Section 21 no-fault eviction notice rather than fixing the issue. Because Section 21 didn't require a reason, the tenant had no way to prove the connection.
The Deregulation Act 2015 introduced some protections against retaliatory eviction, but they only applied in limited circumstances and were difficult to enforce. The Renters' Rights Act 2025 strengthens these protections significantly by abolishing Section 21 entirely. Since your landlord now needs a specific legal ground to evict you, and since there's no ground that says "because the tenant complained about disrepair," the scope for retaliatory eviction is greatly reduced.
If you believe your landlord is pursuing eviction in response to a complaint or repair request, you can raise this as a defence in court proceedings. The court can refuse to grant a possession order if it determines the eviction is retaliatory or a backdoor eviction.