Partygate investigator Sue Gray made a life peer by Keir Starmer

Sue Gray, the civil servant who investigated Partygate and went on to become Sir Keir Starmer’s chief of staff, has been made a life peer, Downing Street said.

Gray is among 30 new Labour peers to be appointed, in a boost for the party’s benches in the House of Lords.

The new appointments also include former shadow cabinet minister Thangam Debbonaire and Liz Truss’s deputy prime minister Dame Therese Coffey.

Gray came to prominence in 2022 with the report into Downing Street parties, and then became Starmer’s chief of staff in opposition before following him into Number 10.

She quit the role in October after a series of internal rows, including a reported dispute over pay cuts among special government advisers and alleged blocking and delaying of government appointments.

Among the other Labour names on the list put forward by Starmer are former MPs Ms Debbonaire, Julie Elliott, Lyn Brown, Steve McCabe and Kevin Brennan, as well as former Welsh first minister Carwyn Jones.

There are also six nominations from Conservative leader Kemi Badenoch, they include Dame Therese as well as former housing minister Rachel Maclean.

There are also two nominations from the Liberal Democrats.

Business secretary Jonathan Reynolds was asked whether Gray could return as a minister if she was given a seat in the Lords.

He told broadcasters that “decisions about Government are for the prime minister, not for me, but I would be really pleased – speculation at this stage – to see a really strong set of people come into the House of Lords to help the Government deliver on its agenda”.

Labour has pledged to reform the House of Lords and has already moved to get rid of hereditary peers. The House of Lords (Hereditary Peers) Bill is making its way through the upper chamber.

It cleared its first hurdle in the Lords in December, having already gone through Commons stages.

The Lords has some 800 members, most of whom are life peers, and adding more Labour peers will boost the party’s representation in the chamber.