The dramatic spending cuts planned by the coalition government have yet to produce any significant divisions on the Conservative side, but that may have changed today with the intervention of Boris Johnson .
Boris, who rarely misses an opportunity to provoke David Cameron, told the London Assembly that he was fighting to protect the capital from the "dramatic and deep cuts" announced by the Chancellor, George Osborne.
In particular, he is desperate to secure the future of the £16bn Crossrail project and vital Tube upgrades.
He said: "It is quite wrong to treat us [London] in the same way as other, more spendthrift areas of Whitehall."
Cameron will be reluctant to concede to Boris. The coalition's mantra remains "We're all in this together": no exceptions can be made (the £110bn NHS budget aside). And among voters there is a widespread perception that London has received preferential treatment for far too long.
But the Prime Minister and his allies will be troubled by Boris's intervention all the same. After Michael Gove was forced to announce that many schools weren't going to be rebuilt after all, we witnessed the unusual spectacle of Conservative MPs (Ian Liddell-Grainger, Philip Davies) against Tory cuts.
As cuts move steadily from the abstract to the specific, we can expect others to join them. In every case, the MP in question will insist that while reducing the country's £149bn Budget deficit remains the priority, an exception should be made for them and their constituents.
Boris, the man still seem by some as the party's leader-in-waiting, could yet become a rallying point for anti-cuts Tories.