Newspaper reports have suggested that Gordon Brown could quit British politics to become the new head of the International Monetary Fund.

According to the Guardian, the chancellor is being considered for the top post by officials at the IMF's Washington headquarters.

The vacancy has arisen because Horst Kohler resigned with immediate effect on Thursday to seek the German presidency.

In post since 1997, Brown has already become the longest serving Labour chancellor.

But by taking the five-year post at the IMF, he would be effectively ruling himself out as Tony Blair's successor as prime minister.

Despite that, one insider was quoted as saying that Brown would not "dismiss things out of hand".

"If it was offered, he would have to think about it seriously," the source said.