Even as the partygate stories continue to mount, some of Boris’s defenders still leap to his defence. This dwindling group of supporters believe the campaign to oust Boris is orchestrated by the PM’s enemies who have an axe to grind. Well, I worked on the Brexit campaign, played a part in helping Boris secure the leadership of the Conservative party and have been one of his staunchest supporters – until now.

Make no mistake: I am – or was – a big fan of the Prime Minister. Boris’s stellar achievements in getting Brexit done and delivering the UK’s world-leading vaccination programme cannot be taken away. When voters handed him a landslide majority in December 2019, the public knew Boris was disorganised and economic with the truth. But the image of the Queen adhering to Covid restrictions and sitting alone in St George’s Chapel grieving for her departed consort, as Number 10 was dancing the night away, symbolises why his magic bond with the public is now damaged beyond repair.

Boris’s line of defence is that he thought the Downing Street party was a ‘work event’. As we all know, ignorance is no defence under the law, but when you are the person who wrote the law there can be no excuse. Yet the PM has feebly attempted to make one by passing the buck: ‘nobody told me’ the Number 10 garden party during lockdown was ‘against the rules,’ he has insisted, while simultaneously stating that he takes full responsibility. The British public may rarely tune in to the cut and thrust of daily politics but this issue has cut-through to the bone. Voters see it for what it is.

You don’t have to take my word for it. Last week, I commissioned Yonder to do a nationally representative poll of over 2,000 voters. The results demonstrate an unprecedented level of anger aimed at a Conservative leader. More than eight in ten voters believe Boris broke the rules, 59 per cent no longer think he should be Prime Minister; and 67 per cent agree he has lied over Partygate.

We do not need to wait for Sue Gray’s report – which has again been delayed because of the Met Police investigation – to hear the verdict in the court of public opinion. Compounding the loss of trust in the Boris brand is a rise in Labour’s support, resulting in a 16 per cent lead. In a general election, this could mean the loss of 194 Conservative seats. Boris the election winner is now Boris the election loser. And for those thinking ahead the poll showed that with Rishi Sunak as leader Labour’s lead is slashed to only four per cent. With Liz Truss, the gap widens in Labour’s favour.

It’s a tragedy how quickly Boris has come unstuck. Back in May 2019, I went to see my close friend Lord Tim Bell to discuss who we should back to take over the reins from Theresa May and ensure Brexit was delivered, not just in name. While it was clear that Boris would win the membership vote he first had to be selected by the MPs to get on the final ballot. Just as he does now, Boris was out of favour with many Tory MPs.

Despite this hurdle, I was convinced that Boris was the man for the job. After the lacklustre leadership of Theresa May – and with the Tory party languishing third in the polls – Conservatives needed someone who could supercharge the party’s appeal to the public. It was clear to me that the only person who could achieve this was Boris. I persuaded Tim to commission YouGov to do a poll of the five most likely leadership candidates. Sure enough, it demonstrated that voting intentions for the Conservatives would receive a ten per cent ‘Boris bounce’ (which was pretty much on the money for the general election landslide under his leadership later that year). Tim agreed to support Boris and wrote to every Conservative MP that Boris was the only candidate who could defeat Jeremy Corbyn. I briefed the media on this letter – which Paul Staines (Guido Fawkes) said ‘was a timely intervention’ that helped Boris win – and the rest is history.

Back then, Bell told Tory MPs that Boris was ‘the only person who can halt an impending disaster’. Now, there is a different message Conservative backbenchers need to hear: if they wait for the May local elections to ditch Boris, they will only succeed in sacrificing many hard-working Conservative councillors. They will also make it more difficult to save their own jobs by delaying a decision that needs to be taken now.

Despite all the fighting talk from Boris’s supporters that he will contest – and win – a confidence vote, this will come to nought. Why? Because, when it comes to ending his own premiership, I am sorry to say that Boris has not just crossed the Rubicon but tripped up over his own shoelaces and fallen headfirst into it. Boris must go.