Education Secretary Bridget Phillipson and fellow minister Alison McGovern are among the Labour figures vying for the party’s deputy leadership.
Former Commons leader Lucy Powell, who was sacked by Sir Keir Starmer in his reshuffle, is also standing in the contest to succeed Angela Rayner.
Commons Foreign Affairs Committee chairwoman Dame Emily Thornberry and backbenchers Bell Ribeiro-Addy and Paula Barker have also said they will stand.
Ms Phillipson appears to be the early frontrunner, securing public backing from several colleagues on social media and in private while vowing to take the fight to Nigel Farage’s Reform UK.
Announcing her bid for the deputy leadership, the Houghton and Sunderland South MP described herself as “a proud working-class woman from the North East” who had gone from “a single-parent family on a tough council street” to the Cabinet table.
Adding that she had taken on “powerful vested interests in the education sector” and “never taken a backwards step”, she pledged to “bring that same determination to every battle ahead of us”.
Ms Phillipson said: “Because, make no mistake, we are in a fight. We all know the dangers Reform poses to 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.”
Birkenhead MP Ms McGovern, a minister in the Ministry of Housing, Communities and Local Government, said Labour had to stand up to the “dark forces of right-wing populism”.
She said: “As we enter the next phase of this Government we need to quickly show that we have learned the lessons of our first year in office and waste no time in delivering on the promise of change that got us elected last year.”
Manchester Central MP Ms Powell had been urged by several of her colleagues to stand for the deputy leadership, and said she had made the decision “after much encouragement”.
Describing herself as “proud” to have served in Sir Keir’s government, Ms Powell said her politics were “rooted” in “an understanding of people’s everyday hopes and fears”.
She said: “As our deputy leader, I would ensure these are at the heart of what we do and how we operate, bringing together all parts of the party and uniting our broad voter coalition.”
Both Prime Minister Sir Keir Starmer and Deputy Prime Minister David Lammy are men representing London constituencies, which has led to calls for Ms Rayner’s successor to be a woman and from northern England.
While this would include Ms Powell, Liverpool Wavertree MP Ms Barker, Ms McGovern and Ms Phillipson, it could count against London-based Ms Ribeiro-Addy and Dame Emily.
Ms Ribeiro-Addy was the first to declare her candidacy, announcing her bid on Monday night.
Seen as coming from the left of the party and supported by Socialist Campaign Group chairman Richard Burgon, she has called for Labour to “go back to the guiding values of our party and movement”.
She has also called for wealth taxes, scrapping the two-child benefit cap, imposing a full arms embargo and sanctions on Israel, unbanning Palestine Action and returning the whip to MPs “punished for voting with their consciences”.
Dame Emily vowed that she would be “a voice for the membership, unions, PLP (Parliamentary Labour Party), and our constituents – not just nod along”.
She also listed welfare, Gaza, a wealth tax and planned changes to special educational needs provision as her key issues.
Nominations for the deputy leadership opened on Tuesday and candidates have until 5pm on Thursday to secure the backing of 80 MPs in order to reach the next round of the contest.
The truncated nomination period has led some to accuse the party leadership of orchestrating a “stitch-up”, while Ms Ribeiro-Addy described it as “unfair”.
She added: “The Labour Party is a broad church and, actually, when we are able to have debates, when we are able to bring forward different views, it actually makes us better.”
A Survation survey of 1,308 Labour members who read the LabourList website suggested Ms Phillipson was the most popular choice for the role.
Among those who expressed an opinion she had a net favourability score – the difference between the percentage who view her as a good candidate as opposed to a bad one – of plus 39, ahead of Dame Emily on plus 20 and Ms McGovern on plus 19.
