Julie Kirkbride, the Conservative MP for Bromsgrove, today defended her expenses claims as "quite separate and quite different" from her husband's, hours after four fifths of voters on an influential Tory website called on her to resign.

In an interview carried out this evening after David Cameron warned that she had “questions to answer”, Ms Kirkbride appeared to blame her husband, Andrew MacKay, the Conservative MP for Bracknell, who announced last week that he will leave Parliament at the next general election, for giving her bad advice when she first became an MP.

While admitting that she knew how her husband had structured his expenses claims, she added that she had gone along with him due to her lack of experience.

“He was told to do that by the Fees Office shortly after we got married, and he took that advice,” she said.

“I was aware that he had that advice, and at the time I was a new MP, taking lots of advice from him on a whole series of issues.

“I did not question it. We both regret that now because Andrew has given up the career that he loves because he made an error of judgment.”

Mr MacKay was forced to announce that he would not stand for re-election after an acrimonious public meeting in his constituency. He had already resigned as a parliamentary aide to Mr Cameron after it emerged that he was claiming second-home expenses of £23,000 on the family home in London — despite not having a property in his Bracknell constituency.

Asked about her decision to pay her sister, Karen Leadley, a £12,000 salary from allowances for part-time secretarial work, Ms Kirkbride replied that she did an “absolutely fantastic job”.

“My sister has been my secretary for about 12 years,” she added. “It has been quite open, everyone has known that my sister worked for me.”

Ms Kirkbride spoke this afternoon after a damning survey on the ConservativeHome website suggested that she should resign. Of the 1,144 voters on the site's monthly survey, 81 per cent said that she should stand down. The survey had then been open for 20 hours.

The site hinted in an editorial this morning that Ms Kirkbride may now be losing the confidence of the party leadership.

Discontent at Ms Kirkbride's record was fuelled last night when the employment of her sister was disclosed in the Daily Telegraph. Tory party sources defended the arrangement, saying that Ms Kirkbride could prove that Ms Leadley genuinely carried out work on her behalf.

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