Angela Eagle and Owen Smith to go head-to-head in race to take on Jeremy Corbyn
Angela Eagle and Owen Smith will go head-to-head on Monday night to decide who will take on Jeremy Corbyn for the Labour leadership.
The pair will take part in a hustings debate in front of the parliamentary Labour party in the House of Commons.
The candidate who receives the least nominations is expected to drop out, with his or her rival becoming a so-called 'unity candidate' to challenge Mr Corbyn.
Ms Eagle launched her campaign on Monday, and many in her team are angered at Mr Smith's decision to enter the race as well.
One told PoliticsHome: "He won't be rewarded for letting Angela do all the work and trying to capitalise on it for himself."
Another said: "What is the point of Owen Smith? He's just Jeremy Corbyn in a suit."
Former shadow work and pensions secretary Mr Smith - who quit the Labour frontbench along with more than 60 of his colleagues - today vowed to be a "radical, credible" alternative to Mr Corbyn as leader.
PoliticsHome understands that many MPs who had previously given their backing to Ms Eagle are now supporting Mr Smith's leadership bid.
A source close to Mr Smith, who is expected to formally launch his campaign on Friday, said: "This has not been an easy decision. It comes after a great deal of reflection and attempts to work with Jeremy to find a way to keep the party united.
"Owen is standing in response to calls from ordinary members, Labour voters and Labour councillors, MPs and MEPs from across the country and from all wings of the party for him to do so.
"Owen is not prepared to stand by when the Labour party is crying out for strong leadership and that's why he is not declaring."
The source added: "This campaign will be a positive campaign based on the future the party can build under a credible, left-wing leader. He will make clear the policies he would pursue as leader and will show why he appeals to a new generation of people desperate for a left-wing Labour government."