The Culture Secretary and Minister for Women and Equalities, Maria Miller, has resigned from the government following days of pressure from Parliamentary colleagues and the media.

Mrs Miller was the minister responsible for steering same-sex marriage through the House of Commons last year. Until today, she was the most senior government minister with a responsibility for LGBT rights issues.

In a letter of resignation to the Prime Minister, Maria Miller said that the pressure on her had “become a distraction from the vital work this government is doing”.

In her letter, Mrs Miller told the Prime Minister that she is “immensely proud” of leading the team with responsibility for “putting in place the legislation to enable all couples to have the opportunity to marry regardless of their sexuality.”

In his reply, Mr Cameron replied: “You have been responsible for successfully handling two of the most controversial issues with which this Government has dealt. As Culture Secretary, you have played a critical role in advancing Britain’s proud record of respect and equality in piloting the Equal Marriage Act through Parliament and onto the Statute Book. There are many people in our country today, and there will be many in the future, who will always be grateful for this very important change, which you did so much to bring about. You have also handled the sensitive subject of press regulation with skill and dedication.”

The former Culture Secretary had been cleared of funding her parent’s home at taxpayers’ expense but was recently ordered to repay £5,800 and apologise to the House of Commons. However, the independent parliamentary commissioner for standards had previously recommended that Mrs Miller should have repaid almost ten times this figure, £45,000, and criticised her attitude towards the inquiry.

Yesterday, Mrs Miller’s then Parliamentary Private Secretary said her role on equal marriage and media reform explains why certain newspapers want her to resign – claims rejected by several commentators across Fleet Street.

In an interview on Tuesday afternoon, Conservative MP Mary Macleod admitted sending a message to other Tory MPs, saying: “I believe there is a media witch-hunt on Maria due to Leveson.

“How do you feel about it? Happy to answer any questions you may have she would really appreciate your support. Many thanks Mary.”

Asked whether she believed newspapers were focusing on the Culture Secretary and Minister for Women and Equalities because of her involvement in the response to the Leveson Inquiry, Ms Mcleod said: “I think it’s Leveson and probably equal marriage as well.”

Defending her colleague, Ms Macleod told Sky News: “I don’t think the public necessarily know all the details of the case because in some of the newspapers it’s been like a witch-hunt where they don’t like the work Maria Miller has done on Leveson and gay marriage. Therefore what they are trying to do is find a way to get her out of her job.”

When asked to name the newspapers behind the witch-hunt, Ms Macleod refused to be drawn.