As the pressure mounts on Minister for Women and Equalities Maria Miller to step down, members of her own party are weighing in to express ‘surprise’ that she has not resigned.

Mrs Miller was last week ordered to repay £5,800 and apologise to MPs after over-claiming expenses on her mortgage.

Conservative MP for Richmond Park Zac Goldsmith, has weighed in to say that he is “surprised” Mrs Miller has not yet stepped down.

Mr Goldsmith told Radio Five Live: “I’m surprised that Maria Miller hasn’t stepped down, I think that it’s – as many of my colleagues have said – it’s a decision for her to make, it’s a decision for David Cameron to make – it’s not an area that most MPs would want to get involved in.

“Her status as a MP should be entirely down to the views of her constituents. They should have the power to remove her tomorrow if a majority believe that is what needs to happen, or they should have the power to give her a new mandate, but this should not be in the power of MPs,” he continued.

A change.org petition has been started which calls for Mrs Miller to “pay back £45,000 in fraudulent expense claims or resign,” has now been signed by 150,000 people.

The Minister for Women and Equalities was responsible for steering the government’s same-sex marriage legislation through the Commons.

Earlier today, an anonymous Conservative backbencher made the claim that Mrs Miller had been kept in post because she’s a woman.

A Downing Street source has said it was for the Prime Minister to choose his cabinet, and plenty of MPs supported Mrs Miller.

Mayor of London Boris Johnson also said on Tuesday’s Today programme: ”I don’t know the facts of the case in great detail but it seems to me she is being hounded quite a lot.

“I suppose my natural sympathy goes out to people being in a hounded situation, how about that? There she is. She’s being hounded.”

The former Conservative cabinet minister and ex-Tory chairman Lord Tebbit accused Mrs Miller of “arrogance” and urged her to step down. 

Work and Pensions Secretary Iain Duncan Smith at the weekend came to the defence of Maria Miller, saying she is facing a possible Tory backlash for “the gay marriage stuff”