A not completely implausible scenario to fear:

Nigel Farage wins Clacton & becomes MP.

In post election Tory chaos, Reform suggest merger with Right-Tory rump.

Tory party splits with Reform uniting with ultra Right Tories & manage to retain party name.

Tory/Reform form 'official' opposition.

Leadership election which Farage wins.

Election 2025 between exhausted Labour party unable to fix the wreckage bequeathed to them by Tories vs. Farage 'the people's savour'!

unthinkable? God I hope so