I’ve been a loyal Conservative voter. Until very recently, I’d exclusively worked for Conservative-leaning publications: the Telegraph, Mail, London Evening Standard, Express and Spectator. Most of my friends and relations are Conservative. But I cannot vote Conservative tomorrow.

Something horrible has happened. The Conservative party lies. It cheats. It bullies. It’s not the wise, gentle, decent party of the postwar era.

How Boris Johnson and Brexit are Berlusconifying Britain | William Davies Read more

I wonder whether Boris Johnson and his squalid associates are Conservatives at all. The Conservativism I understand is about public duty, generosity, the instinct to conserve what is good in our society; the importance of the rule of law and of institutions; suspicion of leaps in the dark. I am thinking of the Conservatism of Burke, Lord Salisbury, Oakeshott.

Johnson has become the leader of a project – his adviser Dominic Cummings is an important part of this – to destroy Conservatism. This is why during his brief term as prime minister Boris Johnson has attacked parliament, mocked the rule of law, abused the monarchy, and shown a total disregard for the truth.

He suppressed a report about Russian interference in British politics, then lied about the reasons. In the past few days, the prime minister has resorted to an ugly racism towards EU nationals in a last-ditch attempt to win votes. In a genuflection to Rupert Murdoch, he’s calling the BBC licence fee into question. Johnson’s Conservatives are a revolutionary sect and should be understood as such.

That’s why many traditional Conservatives have left or been driven out of the party, including David Gauke, Rory Stewart, Amber Rudd, Michael Heseltine, Ken Clarke, Matthew Parris and many others. Former prime minister John Major’s public call not to vote for Johnson was particularly powerful.

The media makes little of this. The denunciation of Jeremy Corbyn by Ian Austin, a Labour politician of negligible importance who had already left the party, got far more coverage than the cry of despair from a former Tory prime minister.

In normal circumstances I would never vote for Labour, let alone Corbyn. I still wouldn’t if I believed the terrible charge that he is an antisemite. There is a problem of antisemitism in the Labour party. And Corbyn has handled the problem badly.

I don’t deny the dreadful actions of some members of his party, but I’m not aware of evidence of Corbyn using derogatory language about Jewish people in the way that Boris Johnson routinely has against black people, gay people and Muslims.

Imagine the collective denunciations of Corbyn had he been guilty of the racist and homophobic remarks attributable to Johnson: phrases such as “piccanninies”, “watermelon smiles” and “bumboys”. There’s a double standard here.

Johnson has not shown the slightest appetite to deal with the virulent Islamophobia that poisons the Conservative party. The mainstream press in Britain has practically ignored this issue. That’s because most British newspapers are themselves Islamophobic. Johnson’s claim that his party has “zero tolerance” for Islamophobia is yet another of the cynical lies that have been the defining feature of his political campaign.

The establishment has always hated radicals like Corbyn. And it’s determined to stop him. Hence the repeated attack that Corbyn can’t be trusted on security and foreign policy.

It’s true that he opposed the three great foreign policy catastrophes of the 21st century: Afghanistan, Iraq and Libya. The damage done by Iraq to our national security was huge. Corbyn was right, while Johnson and the Tory party were enthusiasts for all three.

It’s not just Boris Johnson’s lying. It’s that the media let him get away with it | Peter Oborne Read more

What about Yemen? This election campaign has seen no discussion of Britain’s complicity in Saudi Arabia’s foul war. It’s a shaming omission because according to the United Nations, it has created the greatest humanitarian catastrophe of the century.

Johnson was the foreign secretary in the early stages of this conflict. He was uniquely well-placed, given that Britain was penholder at the United Nations and thanks to our alliance with Saudi Arabia, to avert the calamity. He didn’t lift a finger. Corbyn called for an end to arms sales to Saudi Arabia.

Historians will say that this election has only been about one thing: Brexit. Johnson’s election slogan – “get Brexit done” – is another of his lies. He’s a highly intelligent man and knows perfectly well that Brexit will not be solved if we leave the EU on 31 January. Trading relations with Europe will dominate politics for years to come.

Corbyn is offering a wiser solution to the Brexit problem than Boris Johnson: a final-say referendum offering a choice between remaining on existing terms or continued membership of the customs union.

By contrast, Johnson is offering a guarantee that we will leave in January, followed by a transition period lasting implausibly to the end of next year, after which we could find ourselves operating alone on World Trade Organization rules. He’s in open denial about the consequences for trade with Northern Ireland.

There will be no way back from Johnson’s Brexit. Whatever the possible economic damage inflicted by Corbyn and his chancellor John McDonnell, it will last for a maximum of five years before they can be kicked out by the electorate.

We have a strong Conservative candidate here in Brentford and Isleworth, a local woman named Seena Shah. I’ve seen her in action and in normal times I’d vote for her. Shah represents hope for the future. But she is much too good for Boris Johnson and the wrecking crew that surrounds him. I believe they want to destroy the Britain I’ve lived in and loved all my life.

• Peter Oborne is a journalist and author, and also runs a website about Boris Johnson’s falsehoods

Election night: what to watch for – video explainer