Tory MP Angie Bray became the second ministerial aide to lose her unpaid job with the Government as she was sacked for voting against Lords reform.
Ms Bray was fired as parliamentary private secretary to Cabinet Office Minister Francis Maude after she joined Conservative ranks opposed to plans backed by their leader David Cameron.
Speaking ahead of last night's vote, she told BBC Radio 4's The World at One: "I guess that in normal circumstances those who don't stand by the Government line get the chop so I'll wait for them to do that if that's what they want to do.
"But I don't feel that I need to resign because I don't actually feel that I'm doing anything wrong and certainly I'm not in any way going against what our own Conservative manifesto laid out."
Ms Bray studied medieval history at St Andrews University after leaving the independent Downe House Girls' School in Newbury, Berkshire.
She became a broadcast journalist with British Forces Broadcasting Service and worked on LBC Radio in 1980s before moving to Conservative Central Office and working as a press officer for John Major's successful Tory leadership campaign.
She later became a public affairs consultant before being elected to the Greater London Assembly in 2000 and 2004.
She was elected MP for Ealing Central and Acton at the last general election in May 2010 having unsuccessfully fought the East Ham seat in 1997.
Ms Bray, who lists her Who's Who interests as tennis, music, history, and walking her dogs, wrote on Twitter last night: "Sad2have2oppose Govt on House of Lords reforms but it is bad legislation."