Whenever I see Barry Gardiner or Mark Francois on television, I realise how much Jeremy Corbyn and Boris Johnson have contributed to the zombification of British politics. Reason, logic and the capacity for independent thought are qualities now pretty much irreconcilable with party allegiance.

In the Lib Dems there’s still, I hope, a home for an individual with a conscience. What’s more, ours has always been a grassroots organisation, where it’s ultimately the members who call the shots, which keeps us uniquely in touch with the national psyche.

The nightmare that kept me awake was posing awkwardly at the count as the Tory Brexiter raises her hands in triumph

In Canterbury, where I’d been chosen as our parliamentary candidate in opposition to the incumbent Labour MP, Rosie Duffield, we have what might be called a little local difficulty. In the last election, she won the traditionally Tory seat on the slimmest of margins – fewer than 200 votes – and, while I was confident I could substantially increase the Lib Dem vote on the back of my party’s national resurgence, it was clear there was a danger I’d divide the remainers. That would allow in our common enemy, Anna Firth, the Tory candidate and an avowed hard Brexiter and former Vote Leave stalwart.

I don’t trust Corbyn on Brexit, but I share with many members of my party locally a visceral dread of the Commons being filled with people like Firth. Trying to stop that happening is now more important than ever given Nigel Farage’s unholy alliance with Johnson.

I’ve therefore asked that my local party withdraw my nomination papers to stand for Canterbury. Politics does not always have to be grubby and small-minded; sometimes it’s possible to acknowledge that what’s at stake is more important than party politics – and personal ambition – and we can do what’s right. In this invidious situation, both standing and not standing could be interpreted as weakness. But the nightmare that kept me awake was posing awkwardly at the count beside a vanquished Duffield as the Tory Brexiter raised her hands in triumph. I wanted no part in that.

My party had strained to do a deal with Labour in relation to this seat – putting my formal adoption as its candidate on hold for almost two months – but it proved not to be possible. As with so many things, Corbyn was incapable of adapting to changing times and could not see that my party was now every bit as much of a force to be reckoned with as his, if not more. In the EU elections, we not only beat Labour, but also won more seats than them and the Tories combined.

I know some would wish me to trudge obliviously forward in Canterbury, but that seemed to be something only a zombie would do. We have to take full responsibility for our decisions and we cannot have them made for us. I wish Duffield well and urge her to fight for our country; and, when she hopefully gets to resume her seat in the Commons, to continue to think for herself.

• Tim Walker is the former Liberal Democrat candidate for Canterbury