LONDON: The contest to lead Britain’s defeated opposition Labour Party widened on Thursday after two senior lawmakers added their names to the slate of contenders following the party’s decisive drubbing in a national election last week.

Ed Miliband, the previous leader, quit on Friday, saying he took responsibility for the rout which saw the party virtually wiped out in Scotland and fail to win key swing seats in England from Prime Minister David Cameron’s victorious Conservatives.

On Thursday, Yvette Cooper, the party’s home affairs spokeswoman, said she would run for the leadership, as did Andy Burnham, the party’s health spokesman. Both are considered heavyweight political candidates.

Labour said it would announce its new leader on September 12 after a process which has already triggered a battle to shift its political stance.

Miliband, the previous leader, was seen to have steered the party leftward, prompting senior party figures, including former prime minister Tony Blair, to say it must return to the political centre ground if it is to win again.

The party’s business spokesman Chuka Umunna and Liz Kendall, a health spokeswoman, have already declared they will run for the Labour leadership.