Liz Truss is just 40 days in - and her grip on power is weakening by the hour

Credit: PA

No Prime Minister has got off to such a rocky start as Liz Truss.

Now after just 40 days, it looks like her grip on power is weakening by the hour.

At least three Tory backbenchers have publicly called on her to quit. Behind the scenes very few believe she can survive the debacle of her mini-budget, even after sacking her Chancellor Kwasi Kwarteng.

She won the leadership claiming tax cuts were the route to growth.

But when they were announced, it emerged they would be funded by a massive borrowing spree and there'd been no independent assessment from the OBR.

The turmoil in the markets has yet to subside. Millions will see their mortgage payments rise and pension funds have also been put at risk. Fresh public spending cuts also loom.

Tory MPs I speak to simply don't believe sacking the man who was merely carrying out your plan can save her.

They all seem to agree it's a matter of 'when' not 'if' she goes. One MP even suggested that she could be gone within 24 hours.

Leader of the House of Commons Penny Mordaunt is among the candidates who could replace Truss. Credit: Jacob King/PA

What's much less clear is how Liz Truss could be replaced. Another leadership contest seems out of the question, so it would have to be a 'coronation' - with MPs agreeing on a successor.

There are a number of possible candidates including the former Chancellor Rishi Sunak, Penny Mordaunt - who also ran for the leadership in the summer - and Ben Wallace, the Defence Secretary who didn't throw his hat in the ring last time.

But the party is divided over who really could unite MPs and restore confidence in the Tory Party's ability to manage the economy.

That may give Liz Truss and her dwindling band of supporters some breathing space.

'You can't judge a PM by popularity alone'

Last week, her Business Secretary Jacob Rees-Mogg sprung to her defence when I suggested she had the worst poll ratings of any incumbent.

He told me that you couldn't judge a Prime Minister by popularity alone. He referred to Britain's second Prime Minister the Earl of Wilmington as someone who might have been more unpopular.

For those who don't know, he became Prime Minister in 1742 and lasted less than two years. Not the most flattering comparison you might think from a Cabinet colleague.

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