The last five weeks in British politics have been unlike anything that I have seen, for the Conservative Party this is Dunkirk, says Michael Portillo

The last five weeks in British politics have been unlike anything that I have seen.

The Conservative Party has chosen as its leader Liz Truss. She has lost all her authority, irredeemably in my opinion, in just over a month.

She is the product of an absurd electoral system devised by the party, having to win the votes of Conservative Party members, a tiny unrepresentative minority of British society.

She appealed to their policy preferences – for low taxes – without any plan for how the public finances could be balanced; and once elected, she implemented the scheme, apparently without consulting the Bank of England or the Office for Budget Responsibility or the cabinet or her party.

She set an arbitrary date for the mini budget, and rushed her announcements.

Now she has ditched the Chancellor, Kwasi Kwarteng, who was as irresponsible as she is, and appointed a new one Jeremy Hunt.

She is left with half the tax cuts that were announced in the mini budget, and Jeremy Hunt is preparing to ditch the cut in the basic rate of tax, we hear.

I fear that the markets have decided that she is not up to the job. Her party thinks that too, but it lacks mechanisms to get rid of her. There is no consensus on a successor, yet nobody who is not blinded by devotion to her, can imagine that she can go on for long, late alone until a general election.

The Conservative Party needs somehow to settle on a successor who will be chosen by acclamation because there is no time for an election.

I can think only of Rishi Sunak. Liz Truss needs to be persuaded to cooperate: to stand down in an orderly way if an overnight change of prime minister can be engineered.

I believe that is the only option since it is not possible to imagine that Liz Truss stays in office, nor can we contemplate another lengthy, chaotic and disastrous Conservative leadership election.

The Labour Party - and probably the public - wants a general election, and they have justice on their side, given the pandemonium devised by the Conservatives. It is not easy to see how we get from here to a general election, but I have a feeling that we will get to one by means unforeseeable now, unless the Tories bring about a swift change of prime minister.

The Conservatives have a reputation for ruthlessness and for loving power. They used to have a reputation for economic competence. If anything is to be salvaged, they need to be merciless now as never in their history. The chairman of the 1922 committee, Sir Graham Brady, has to assume a role never played by any predecessor, of convening the party in parliament and the prime minister to bring this catastrophe to an end. For the Conservative Party this is Dunkirk.