Shop workers union USDAW has nomindated Keir Starmer for leader and Angela Rayner for deputy leader of the Labour Party.
It means Mr Starmer is through to the ballot for next stage of the Labour leadership contest.
Ms Rayner needs one more nomination to secure her place in the next stage of the contest.
The decision was taken at Usdaw’s Central Office in Manchester by the union’s lay member elected Executive Council.
Paddy Lillis - Usdaw General Secretary said : “Usdaw believes that Keir Starmer and Angela Rayner are the right leadership team to unite and rebuild Labour after a devastating election loss.
"Our members desperately need Labour in power, they cannot afford another decade of Conservative governments attacking workers’ rights, incomes and public services.
“The Labour Party must be led by someone who can persuade voters that they have what it takes to be a Prime Minister and we are a government in waiting.
"That is at the heart of Usdaw’s decision to make these nominations.”
Keir Starmer said: “I’m honoured to have received Usdaw’s endorsement for the Labour leadership.
"Our campaign is building unity across the labour movement, amongst trade unionists and members.
“Usdaw represent over 400,000 workers and fights every day for its members and for a fairer society.
“If I’m elected leader, Labour will stand shoulder to shoulder with the trade union movement as we take on the Tories and rebuild trust with working people.".
