A second ministerial aide has confirmed they will risk being sacked from the government by rebelling on Lords reform in a crucial series of votes on Tuesday evening.
In her first media interview on the contentious reform Bill, Angie Bray, the Parliamentary Private Secretary to the Cabinet Office minister Francis Maude, urged the government to stop "wasting time" on Lords reform and focus on "the more important issues".
Bray has told HuffPost that she won't resign ahead of a crunch vote expected at ten o'clock on Tuesday night, where she will defy the government whip and vote against the "programme motion", which will decide how long MPs spend discussing the Bill.
She expects to be sacked from the government shortly after the vote, but appears to be signalling to the administration that it should show some leniency on an issue of conscience.
If the government loses the programme motion then in effect it loses control of its legislative agenda on Lords reform, allowing Labour and Tory rebels to filibuster the Bill and talk it out of parliament.
Failure to get the Bill through the Commons would further sour coalition relations and upset the Lib Dem MPs who are the most keen to see through the reforms.
Bray told HuffPost: "I will be voting against the programme motion and I’ll also be voting against second reading because I don't believe this in any way advances the interest of parliament or the country.
"I think for most people this is a rather arcane constitutional issue given the awful time we're all going through.
"I would hope that common sense would still prevail and we can step back from wasting time on this and focus on the more important issues," she added.
But Bray has indicated that if she is to leave the government she wants to be sacked rather than resign. "I won't be resigning because it's for the government to take a view on my voting behaviour. But I expect normal rules will apply and I will lose my job, which is disappointing.
"But this is a really important issue about the way we govern this country and it's not something I'm prepared to back down on," she said.
"Obviously I will be sorry to lose my job as PPS to Francis Maude because I happen to think he's doing some important work saving the taxpayer billons of pounds. I really enjoy being part of his team."
Bray's comments mean two junior members of the government have now confirmed they will risk their jobs and vote against the coalition whip later.
Conor Burns has been clear for several weeks that he feels unable to support the Lords Reform Bill and has given several interviews where he has pledged to vote against the programme motion.
Burns was one of a horde of Tory MPs who openly mocked and jeered at Nick Clegg during a stormy session in the Commons on Monday.
Clegg struggled to make progress in his speech outlining the virtues of his reforms, amid continued interruptions from backbench Tories.
Labour supports the principle of Lords reform but feels the Bill being considered is flawed. Labour MPs will vote in favour of the Bill at second reading tonight but against the programme motion.
The government can be assured of wining the second reading vote - which technically allows the Bill to proceed to the next stage in the Commons - but is likely to lose the programme motion since up to 100 Tory MPs are likely to defy the whip and vote against it.
Senior Lib Dems close to Nick Clegg have warned that the party could exact revenge if the Lords reforms are scuppered by blocking David Cameron's attempts to reduce the number of MPs by 50 and radically redraw constituency boundaries for the next election.
The changes, which MPs still have to vote on, are likely to reduce what many see as an inbuilt advantage to Labour in the electoral system.
Although Lords reform garners almost no interest among the public it has the potential to further erode relations within the coalition in what threatens to be a tit-for-tat series of arguments.
These arguably started when Lib Dems abstained in a Commons motion calling for culture secretary Jeremy Hunt to be referred to the independent watchdog for ministerial standards following his appearance before the Leveson inquiry.
Tory MPs were furious that Nick Clegg called on his MPs not to support a coalition minister, a decision that has led to a deep and genuine resentment of both Clegg and his parliamentary colleagues.
Although Tory MPs will not say this on-record, there are some who might have tolerated the Lords Reform Bill as a coalition measure, had it not been for the Lib Dems' failure to support Hunt when he was in a tight spot.
As we go into Tuesday night's votes Westminster will be watching to see if any more junior members of the government resign or abstain, what treatment is meted out on them by David Cameron, and whether the Lib Dems overtly threaten to block the PM's boundary changes as a result of losing the programme motion.
The long-term health of the coalition depends on whether Tuesday night's vote becomes merely a single defeat for the government and a major embarrassment for Nick Clegg, or if it comes to be seen as another phase in what some see as a growing war of attrition within the coalition which could lead to its early break-up.