Kate WhannelPolitical reporter
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Education Secretary Bridget Phillipson has entered the contest to be Labour's deputy leader, becoming the most senior figure to put her name forward so far.
Bell Ribeiro-Addy, MP for Clapham and Brixton Hill, is so far the only other declared candidate in the race to replace Angela Rayner in the deputy leader role.
Lucy Powell, who was sacked from her government job of leader of the House of Commons last week, is also expected to announce her candidacy.
Foreign affairs committee chair Emily Thornberry has said she is considering entering, while former Transport Secretary Louise Haigh and Tooting MP Rosena Allin-Khan have ruled themselves out.
Candidates have until Thursday evening to get nominations from at least 80 Labour MPs in order to take part in the contest.
They will also need the backing of either 5% of local parties, or three Labour-affiliated groups, including two unions.
Those who clear the bar face a vote by party members, with the winner announced on 25 October.
Some in Labour have criticised the tight three-day window for getting MP nominations, which was announced by party bosses on Monday.
Ribeiro-Addy, a backbencher from the left of the party, said: "It is absolutely unfair, and I don't think it's what the membership want".
Speaking to the BBC Radio 4's Today programme, she said Labour needed to have a discussion about "what's gone wrong" with the party's direction.
She added that many members and voters were unhappy about "the situation in Gaza, the winter fuel allowances, the welfare cuts".
Announcing her decision to run, Phillipson described herself as a "proud working-class woman from the North East" who could bring "determination to every battle ahead of us".
"Because make no mistake: We are in a fight. We all know the dangers Reform poses our country.
"But not only am I ready for it: I've proven we can do it. I've shown we can beat Farage in the North East, while staying true to the Labour Party's values of equality, fairness and social justice."
Asked about the contest on BBC Breakfast, Health Secretary Wes Streeting said he had not yet made up his mind about who he would support.
He added that deputy leadership contests usually took place after Labour had lost an election, but this one was taking "place in the context of a party who are in government, and whose focus has got to be delivering the change we promised at the last election".
Whoever wins the contest, David Lammy will remain as deputy prime minister - a role which is appointed by the prime minister, rather than decided by Labour Party members.