Iain Duncan Smith’s resignation as work and pensions secretary on Friday has brought a split in Britain’s ruling Conservative Party to the forefront that Prime Minister David Cameron may no longer be able to contain.

Robert Colvile reports for Politico that, on the face of it, there is little about Duncan Smith’s resignation that makes sense.

The rightwinger ostensibly stepped down over cuts to disability benefits — except those cuts were already being abandoned and now certainly have no chance of coming to pass.

“Some people have linked Duncan Smith’s departure to the Brexit referendum, given his lifelong Euroskepticism,” writes Colvile. The minister was among few in the cabinet campaigning openly for a British exit from the European Union, despite Cameron’s support for staying in.

But Colvile believes there is a simpler explanation: Duncan Smith minister simply had enough of George Osborne, the budget-cutting chancellor of the exchequer.

Divisions

Part of the Tory right has been dissatisfied with the Cameron-Osborne project from the start, dismissing its support for foreign aid and gay marriage as liberal distractions and rejecting the incessant focus on macroeconomic stability.

Matthew d’Ancona writes in The Guardian that there has been a personal dimension to all this: a resentment among reactionary backbenchers who feel that only those who are trusted by the centrist Cameron and Osborne manage to get anywhere.

In practice, the prime minister is once again at the helm of a coalition, argues d’Ancona, “more fractious and riven with ancestral passions than its Conservative-Liberal Democrat predecessor.”

There is the Cameron party, committed to staying in the EU, in no hurry to see Cameron leave the prime ministership and hopeful that Osborne will succeed him.

And there is the Brexit party, “loose-knit but united by the wish to see Britain escape the EU and for the Cameron-Osborne duopoly to come to an end.” With a few exceptions, its members want Boris Johnson as leader — “even if they are not sure why.”

The outgoing mayor of London is if anything more liberal than Osborne, ever pushing for lower taxes, fewer regulations and less welfare. The only substantial difference they have is over Europe.

But then that’s all the matters to the old Tory right anyway.

Leadership challenge

The Financial Times reports that a leadership challenge is now expected whatever the outcome of the EU referendum in June may be.

If a majority votes to leave, Cameron’s position could become untenable.

But even if a majority votes to stay in, the Euroskeptic right of his own party may no longer be content to wait for Cameron to fulfill his promise and step down in time for the next election.

“There are plenty of grumbling Conservative backbenchers and this row has confirmed their worst fears about the style of the Cameron-Osborne leadership,” according to the Financial Times.

“Madness”

The prospect of a leadership contest exasperates d’Ancona.

It is beyond extraordinary that, less than a year after it won a historic election victory, led by a prime minister who has already announced his departure, the Conservative Party is playing with the gelignite of a wholly unnecessary leadership race.

“This is patently madness,” he writes, “but it is a madness toward which the Tory tribe is lurching, encouraged by Duncan Smith and by a yearning for Boris Johnson.”