Angela Eagle has formally launched her bid to oust Jeremy Corbyn as leader of the Labour Party.
In a speech in London, the former shadow cabinet minister said that she would be able to "bring our party together again".
Her announcement looks set to trigger civil war within the party, with Mr Corbyn likely to fight to ensure that his name is on the ballot paper for a vote of the party's members, among whom he has strong support.
Ms Eagle's leadership bid comes after 172 Labour MPs indicated that they had no confidence in Mr Corbyn in a vote in which he garnered the support of just 40 Westminster colleagues.
Angela Eagle insisted she has not embarked on a political "suicide mission" as she launched her bid to topple Jeremy Corbyn.
The former shadow business secretary said she could make Labour electable again after the "howl of pain" expressed in the Brexit vote.
"I don't go in for suicide missions," Ms Eagle said when asked if her chances were doomed if Mr Corbyn is allowed on the ballot paper.
Ms Eagle insisted it was a matter for the party's national executive committee whether Mr Corbyn needed to be nominated by 51 MPs and MEPs to be allowed to stand as a candidate.
Taking a swipe at Mr Corbyn, Ms Eagle said: