The Conservative politician Louise Mensch has resigned as the MP for Corby. She says she was "devastated by the necessary decision".
Ms Mensch beat Labour minister Phil Hope by 1,951 votes in the May 2010 General Election. The resignation will mean a by-election in a marginal seat.
Louise Mensch is quitting the Commons to move to the United States with her family.
In her resignation letter, Mrs Mensch thanked the Prime Minister for all his support, but said she had “been struggling for some time to find the best outcome for my family life, and have decided, in order to keep us together, to move to New York.”
She continued: “It has been an honour to serve the people of Corby and East Northamptonshire. Whether it has been supporting Corby's new free school, or fighting for the truth on the Cube overspend and land development deals, or striving to protect the East Northamptonshire countryside, in my work as the local MP I have always been struck, as I said in my maiden speech, by the pride people have in our area.”
In the Prime Minister’s reply, he said it was with “enormous regret that I accept your resignation as the Member of Parliament for Corby and East Northamptonshire, a seat that had been Labour for thirteen years before you. I do so only because I wish to support you in acting in the best interests of your family, which must come first.”
The Prime Minister went on to warmly thank Mrs Mensch for her service and said that she had been “a truly inspiring Member of Parliament, championing your constituency of Corby with flair and energy over the past two and half years, while also serving with great distinction on the House of Commons Culture, Media and Sport Select Committee.”