Angela Eagle, the former shadow business secretary, has formally launched her widely predicted bid to take over as leader of the Labour party, slamming current leader Jeremy Corbyn.
Eagle branded her campaign as one to re-unify the party after weeks of rebellion with Labour's parliamentary ranks, including a vote of no confidence which saw 172 Labour MPs vote against Corbyn - with just 40 supporting of their leader.
More than 60 Labour MPs have resigned shadow cabinet, front bench and parliamentary aide roles since the European referendum, and Eagle argued that there is a national need for strong, united opposition.
“Jeremy Corbyn is unable to provide the leadership that this huge task needs,” she said earlier today, addressing MPs including the former leader Harriet Harman and prominent Brexit campaigner Gisela Stuart. “I believe I can.”
Eagle said that under Corbyn, the party had failed to convince the public of its ability to form an alternative government.
"The blunt truth is that the country doesn't believe that when they look at us right now. But they will if I win this fight," she said, adding that the party's greatest achievements were only possible when it was in power.
"I'm not here for a Labour party that just takes part. I'm here to win," Eagle said.
However, while Eagle stressed that her challenge to Corbyn would not be "a suicide mission" given the leader's strong support among Labour members, she also made a public appeal to voters to join the party and boost her campaign.
"I need those who want a better Labour party and a better politics to join Labour right now. Help me change Labour for the better," she said.
It remains unclear whether Corbyn will automatically be on the ballot paper to oppose Eagle's challenge.
Labour's rebels argue that he requires the support of 20 per cent of Labour MPs and MEPs, equivalent to 50 backers.
The party's national executive committee will meet later this week to decide on the rules of the leadership election, but Corbyn has already made clear that he will pursue legal action if blocked from running.
Eagle was pensions minister for one year under Gordon Brown, and was made shadow chief secretary to the Treasury in 2010 under then-leader Ed Miliband.