By Ross Hawkins
BBC political correspondent
David Cameron has angered some of his backbenchers
As David Cameron was setting out his programme for coalition government, more than 100 of his backbenchers were voting against his plans to get more influence over a powerful committee of Conservative MPs.
As its name suggests backbenchers on the 1922 Committee have been keeping the Tory leadership informed, and occasionally in check, for many decades.
Its chairman presides over the election of the Conservative leader. It has serious clout.
But the prime minister has pushed though changes likely to mean that, from now on, members of the government will have a vote in elections to select the members in charge of the committee.
That has left Tory backbenchers suspicious Mr Cameron will try to get his favoured candidates elected, and guarantee himself an easy ride from the 1922 in the future.
Some, to quote an unhappy MP, are spitting nails.
Their fury is all the greater because the changes, and the poll to confirm them, were announced without warning at a meeting many thought was called to ask their opinions on the coalition deal.
One backbencher, Peter Bone, said: "We were bounced into this. We had no notice about it.
It is the timing of this change that has surprised many, with the Tory leader making his move while resentment about deals with the Liberal Democrats simmers
"What trade union could suddenly change the constitution, change the electorate and say: 'By the way the ballot box is opening in half an hour and it will close in two hours the following day'?"
Only a handful of the angry MPs have expressed their feelings so publicly. Many more grumble privately.
But 118 voted against the changes. That was not enough to win - 168 supported Mr Cameron's point of view - but sufficient to get their point of view noticed.
Unhappy backbenchers are, of course, a fact of life for all prime ministers.
In coalition government, with uncomfortable compromises the order of the day, it is no surprise that the unhappiness is heightened.
But it is the timing of this change that has surprised many, with the Tory leader making his move while resentment about deals with the Liberal Democrats simmers.
Some of those left angry by the change talk of legal action, others of the possibility of setting up a new committee.
Neither option is being taken forward for now, although a number of MPs have questioned the wording of the ballot and suggested it might not be sufficiently clear to give ministers a vote.
Their arguments will be detailed, and to those outside Westminster potentially arcane.
But angry government backbenchers matter because the coalition rests on the prime minister's ability to command the confidence of the House.
David Cameron may well have simultaneously weakened a potentially hostile committee, and stoked the resentment of those who could make his life difficult in the future.