Last week, I wrote of George Osborne as favourite to replace David Cameron as leader of the Conservatives. This is almost certainly still true. But Osborne’s reputation is – rightly – plummeting. As I predicted might happen (though can’t say I saw it happening quite so quickly), the planned changes to tax credits (the ones with which David Cameron is “delighted“) are rapidly bringing down the price of George’s stock.

We’ve been here before. But “which here?” is the question on commentators lips. There are two scenarios being discussed. This is either George’s pasty tax or his poll tax.

iI it is his poll tax, then it is game over for George (note that isn’t necessarily true for the Tories – who went on to win in 1992 after the poll tax). If these moves prove as universally damaging as that iconic moment, he cannot last. David Cameron will have to cut him loose and move his allegiance and the Chancellorship to one of George’s rivals.

That would be damaging for all concerned.

For Cameron who would be both tainted by association (that quote linked to above will haunt him whatever happens) and also seen as an inconsistent friend, letting go his closest ally. he would also have age old problem of an ambitious rival in Number 11 – and this time, one less willing to wait.

it would obviously damage Osborne’s political career – probably fatally. I don’t see a way a man who has staked his reputation on his economic credibility comes back from being sacked as Chancellor.

But Osborne makes for a fierce rival – as Labour know to their cost. So whoever replaces Osborne will find themselves facing a well briefed (and – in the Tory Party at least – well liked) enemy with the backbench freedom to speak as he chooses.

However, this may well be simply another spoke in Osborne’s up and down cycle of politics. In 2012 there was real speculation that Osborne would not survive his Omnishambles budget. The granny tax, the pasty tax and the tax cut for millionaires were all held up as appalling political mistakes lacking in the most basic of nous. For a while George looked very wobbly.

In the end, oddly, the Omnishambles Budget proved more damaging for Labour than for George. It was far enough out from an election that he was able to undo most of the harm to his reputation, while in the meantime, Labour took its foot off the gas, convinced the Tories credibility had been shot.

The same could easily happen here. Osborne is making the Autumn Statement to the House of Commons in November and could well use this opportunity to make changes to these plans to protect more people from them. I doubt at this point he can drop them altogether. I would expect a gentle curve to a better place rather than a u-turn, but watch how it will be briefed. I suspect we will hear the phrase “Osborne has listened” a lot.

This measure is early enough in a Parliament to be mostly forgotten and absorbed by the time of the next election. If Osborne can manage his way through the reputation damage limitation, this is likely to be more 2012 than 1990.

A week is a long time in politics, but five years is much, much longer. I don’t yet believe that this error will bring Osborne down. But it has proved not only to Labour supporters like myself, but more importantly to Tory cheerleaders that the man is both fallible and beatable. Neither are attractive qualities in a leader.