Sir Keir Starmer is expected to nominate his former top adviser Sue Gray for a seat in the House of Lords.
The former civil servant, who sprang to fame with her 2022 report into the Partygate scandal, is expected to be among a raft of new Labour peerages to be announced on Thursday.
It comes only two months after she left her role as the prime minister’s chief of staff in October, amid internal rows over her influence.
She was then appointed to a newly-created nations and regions role in No 10, but it was confirmed last month she would not be taking up that position.
A number of Conservatives will also be appointed to the upper chamber as part of the announcements on Thursday.
Labour said in 2022 that it planned to abolish the 805-member Lords, replacing it with a “new, reformed upper chamber”.
But this was watered down before July’s election, with Labour committing to consult on plans for an alternative second chamber, whilst immediately axing the 92 places for hereditary peers and introducing a retirement age of 80.
The party also vowed to introduce new rules on participation, and a new process to make it easier to remove “disgraced” peers.
According to The Sun newspaper, Ms Gray is set to be among 30 new Labour peers nominated by the prime minister this week.
Sir Keir will reportedly justify the extra appointments on the basis that Labour has a smaller presence in the upper chamber than in the House of Commons.
The Conservatives have the most peers, with 273, whilst Labour has 187 and the Liberal Democrats have 78.
There are also 184 “crossbench” peers who are not aligned to any party.
