LONDON, (Reuters) – A third senior minister quit the  British government yesterday, calling on Prime Minister Gordon  Brown to quit to improve his party’s chances at a general  election due within a year.

James Purnell’s resignation, announced in a letter printed  by The Times newspaper, is a direct attack on Brown’s authority  and increases the possibility of a challenge to his leadership  of the ruling Labour Party.

Purnell, work and pensions secretary, a rising star in the  Labour Party, is the third cabinet minister this week to resign.  He said he was not seeking the party leadership but his dramatic  intervention could embolden a challenger to emerge.

News of the letter broke as polls were closing in local and  European elections in which Labour, in power for 12 years, was  expected to suffer heavy losses at the hands of the centre-right  opposition Conservatives.

Brown only found out about Purnell’s resignation at about  the same time that he went public with the news, according to  Brown’s spokesman.

The spokesman said Brown was disappointed by the news but   would focus on restructuring the government to guide the economy  through the downturn and rebuild trust in parliament, which has  been tarnished by a scandal over politicians’ perks.
Brown is expected to reshuffle his government soon after  Thursday’s elections.
Purnell’s spokesman could not be reached for comment.

The opposition Conservatives stepped up their calls for an  immediate national election. “It’s clear that we have a  completely paralysed government at the moment,” Conservative  economics spokesman George Osborne told Sky News.

Labour has slumped in the opinion polls as the government  struggles to counter a severe recession. In recent weeks, Labour  and the other main parties have all been damaged by reports of  members of parliament abusing their expense accounts.