Only days ago Philip Hammond faced the sack from Theresa May's cabinet. Now the chancellor is the only figure of stature in the cabinet who can salvage something from the wreckage of the prime minister's "Brexit" election.

Colleagues say Boris Johnson, the foreign secretary, is already plotting to grab the keys to 10 Downing Street. Mr Hammond, the government's grown-up, is more concerned with securing a halfway sensible outcome to the Brexit negotiations.

Mrs May's joint chiefs of staff Nicholas Timothy and Fiona Hill made no secret that Mr Hammond was first on their hit list when, as they imagined, the prime minister swept back into office last week. The chancellor was frozen out of the election campaign, giving Jeremy Corbyn's Labour a free hand in promoting a high­-spending, high-­tax alternative to Conservative austerity.

That was then. Mrs May lost her majority and her chiefs of staff have lost their jobs. Now Mr Hammond has the political leverage in the relationship between Downing Street neighbours. As long as she harbours hopes of clinging on to Number 10, the prime minister cannot afford to lose him.

The breakdown in relations between the two was in part a Whitehall power struggle. Mrs May and her advisers wanted to tame the Treasury; Mr Hammond made no secret of his disagreement with some of the more interventionist economics promoted by Mr Timothy.

The prime minister's gang thought they could tame the Treasury once and for all. The argument that mattered, though, was over the nature of Brexit. While Mrs May slid into a policy of appeasement of the hard Brexiters in her party, the chancellor consistently made the case for a deal that would safeguard the nation's economy.

A pragmatist rather than a natural Europhile, he had some support in the cabinet - Amber Rudd, Damian Green and Greg Clark are often mentioned as allies. The chancellor, however, was outgunned.

Now the political dynamics have reversed. The voters rejected Mrs May's call for a hard Brexit that would have taken Britain out of the single market and customs union; Ruth Davidson, the Scottish Conservative leader, has thrown the weight of her new MPs behind a soft Brexit; and Northern Ireland's Democratic Unionist party is likely to make its support for the government conditional on a Brexit deal that preserves Ireland's open border.

Mr Hammond's position is strengthened further by the fact that most of the serious work on Brexit has been done by the Treasury.

Mr Johnson may think a favourable deal is guaranteed by Britain's imports of Italian prosecco and German cars.

The Treasury has examined in detail ways Britain can keep open trade and investment channels in a new arrangement with the EU. It has also made the case for a sensible immigration policy.

"Spreadsheet Phil", as the chancellor is sometimes known in Whitehall, has the experience and temperament for complicated negotiations.

There is no guarantee that a sensible policy will emerge from the ashes of Mrs May's election defeat. Mr Johnson is not alone in seeing the Brexit vote and its aftermath as an opportunity for personal advancement rather than a threat to national prosperity and security.

Mr Hammond, though, has the opportunity to make the counter case. He should gather around him those sensible Tories ready to put the nation first.

philip.stephens@ft.com