How much longer can Theresa May remain at Number 10 if, yet again, Parliament throws out her Brexit withdrawal plan, asks Chris Moncrieff...

Is the curtain finally going to close on Theresa May? Another wounding defeat on her much-maligned Brexit withdrawal deal now seems inevitable in the Commons on Tuesday. But for how much longer can this unedifying saga continue?

The Prime Minister has firmly and bravely stuck to her plan in the face of the many slings and arrows her political opponents — and some of her so-called supporters — have continued to hurl at her.

But despite new warnings being issued by some of her friends about the possibly dire consequences of voting the measure down, yet again, it seems likely their pleas will fall on deaf ears.

It is now becoming obvious the House of Commons, with its present composition, may never accept her plan — or come up with a viable alternative.

But throughout, May has demonstrated the mettle required for a Prime Minister struggling through politically charged and difficult times, in sticking to her guns and confronting the fury of Westminster.

She has dealt not only with the overwhelming criticisms of her colleagues, but also with what appears to be a stubborn set of negotiators in Brussels.

Sometimes — but not often — they have uttered honeyed words, but their general attitude has been mulish, as if to warn any other EU states of what they might come up against if they expressed a desire to quit, too.

With Theresa May on a distinct wobble, the small army of her would-be successors will already be oiling their bandwagons to ensure they are in perfect running order for a leadership contest — which they likely suspect could be sooner rather than later.

The usual suspects are in the frame, although I would stick my neck out so far as to suggest that neither Boris Johnson nor Michael Gove will be the new tenants at Number 10.

The Chancellor 'Spreadsheet' Philip Hammond is arguably too grey and tedious a figure to spark much enthusiasm from would-be voters.

One possible candidate though who should not be written off, is Andrea Leadsom, Leader of the Commons. Unlike some of her Cabinet colleagues, Leadsom has been totally loyal to the Prime Minister throughout the recent traumatic parliamentary months we've been experiencing.

She is outspoken, fair and has won Brownie points for standing up to Speaker, John Bercow, who more than once has been insufferably offensive towards her. Leadsom could well become the candidate who surprises all the other so-called favourite contenders.

It is probably premature to start laying firm bets, but May could soon be clinging on to power by just her fingertips.

Are these the most heartening words said yet among the millions of words uttered as the Brexit juggernaut trundles along on its seemingly endless journey?

Dr Liam Fox, the International Trade Secretary, said this the other day: "There is a world beyond Europe and there will be a time beyond Brexit."

I am glad he thinks so, because I for one was beginning to wonder... If he is right, it will at least give our MPs something fresh to squabble about. Which would certainly be a relief.