As they say in Westminster, the 'optics' were awful. On the day that 710 fresh 'asylum seekers' had escaped the war-torn hell hole of northern France to descend on British beaches, the immigration minister responsible was preoccupied with other matters entirely.

Mike Tapp should be spending every waking minute trying to meet Labour's pledge to 'stop the boats'.

Instead, even as hundreds more unvetted males disembarked from their Border Force water-taxis (including in his own constituency of Dover and Deal), he was plotting in a Westminster watering-hole to replace Keir Starmer with his own chum, ex-health secretary Wes Streeting.

'Any day could be the day of the coup,' Tapp told a colleague. 'If I could, like, tomorrow, click my fingers, there'd be a new Prime Minister – Wes Streeting.'

Tapp initially denied having said all this – until the Daily Mail produced a recording of him saying it. As so often with this government, it was less The West Wing and more The Thick Of It. There could hardly be a more enraging example of the self-serving chaos that has gripped this government as the country burns.

It pains me to say all this because I was a Labour minister myself, under Gordon Brown and Tony Blair. Yes, we had our difficulties in the aftermath of the Great Financial Crisis – but we never stooped to antics remotely close to these.

This government's abject failures on illegal migration – the most salient domestic issue – are bad enough. But on more existential questions such as the defence of the realm, it gets even worse.

Just days ago, after Royal Navy commandos had intercepted one of Putin's 'shadow fleet' tankers carrying sanctioned oil through the English Channel, a Russian frigate fired warning shots near a British yacht crewed by a retired couple in the same stretch of water.

For years, Russian actors have been preparing for a Cold War-style campaign of sabotage by mapping our critical undersea infrastructure. Only this week, it emerged in court that Kremlin propagandists had carried out a sleazy plot to smear the British prime minister by paying Ukrainians to firebomb his property, before spreading false rumours that they were 'rent boys'.

Meanwhile, Donald Trump has made it clear that Europe can no longer enjoy by right the toasty warmth of Uncle Sam's security blanket.

Yet where is the British government in all this? Expending its energy scheming to oust a Prime Minister who, for all his failings, won a landslide election less than two years ago. Countless other areas of our national life are in need of desperate attention – the economy, for one.

Most people's wages have been stagnant for almost 20 years. The 'cost of living crisis' never seems to end. A generation of young people risk being locked out of work altogether: youth unemployment now stands at 16 per cent, while the Government has hiked national insurance, business rates and the minimum wage beyond anything the market can sustain.

Some 27 young non-EU migrants are being hired for every Brit under 25, recent analysis revealed.

You get the picture. Is this the time for Labour to engage in a blood sacrifice?

Two years into Tony Blair's first government, in 1999, Labour had introduced the National Minimum Wage, brokered the Good Friday Agreement and paved the way for Scottish and Welsh devolution, questionable though it may look today.

Governments – especially those, like the current one, that have enjoyed a long spell in opposition – should be being transformational at this stage of their terms.

I believe Starmer is the worst prime minister of my lifetime and I include Liz Truss, who at least knew what direction she wanted to take the country. Starmer looks like what he is: a procedure-bound Islington 'human rights' lawyer out of his depth. But despite that, I'm not sure getting rid of him is the answer. After all, which, if any, of the putative challengers to his throne suggest they'd do the job better?

Andy Burnham has a human touch that Starmer lacks – but that's about it. I suspect, if he wins the leadership, he too will implode within weeks. And who else is there? If Burnham fails it may be Wes Streeting. At least has a political philosophy but he is seen by the Labour membership as too Right-wing!

Or perhaps Ed Miliband, who is said to be on resignation watch anyway. Or even ex-deputy prime minister Angela Rayner, if she has truly escaped the murky questions surrounding her tax affairs.

None of these chancers look to me like a Gladstone or a Churchill in the making. We don't have much time to sort out the problems we face. If we are prevented in doing so because of their pathetic manoeuvring, history – to say nothing of the voters – will deliver a terrible reckoning.

Tom Harris is a former Scottish Labour MP and Transport Minister