Louise Mensch, the outspoken Conservative MP for Corby and East Northamptonshire, has resigned.
Mensch announced that she has found it too difficult to maintain a balance between her family responsibilities and her political career.
She and her three children will move to New York, to live with husband Peter, who manages the band Metallica.
Mensch tweeted:" I am devastated by the necessary decision that I have had to announce today. It has been an honour serving the people of [Corby and East Northamptonshire].
"It has, however, proved impossible to balance the needs of my family. I have written to the Prime Minister; this will be published in due course."
She told the Northamptonshire Telegraph: "I am completely devastated. It has been unbelievably difficult to manage family life.
"We have been trying to find a way forward with the Prime Minister's officer, but I just can't spend as much time with my children as I want to."
Originally Mensch had planned to make the move to the states following the 2015 general election, but she wanted to time the move so as not to give her children the minimum amount of disruption.
She added: "Every family is different and another mother might feel she can manage things.
"It's been an honour to represent the people of Corby and East Northants and I will miss them."
The surprise resignation brings a sudden halt to a political career that saw the independent and outspoken Mensch become a polarising public figure.
Hailed by many Tory supporters as one of the stronger young women of the party, Mensch was an important tool in the party's attempts to distance itself from the middle-aged, middle-class stereotype. Her celebrity even saw her pose for a GQ photo shoot, while she admitted the use of class a drugs in her youth.
Her strident political opinions often led her into high profile clashes with rival politicians, while she was one of the party's more active Twitter users. Her seemingly pro-Murdoch and News International stance as a member of the culture media and sport select committee led to public sparring matches with similarly outspoken Labour member Tom Watson.
Mensch's high visibility and outspoken nature also meant she attracted negative attention from some of the more venemous members of the public. In April she published typical examples of the sexist and aggressive abuse on Twitter in an attempt to expose the bullying of women online.
In June a man was given a 26-week prison sentence after sending Mensch messages telling her she would have to choose which of her children would die.