Keir Starmer has appointed 25 Labour peers including a number of former senior government and party aides in a bid to strengthen his hand in the House of Lords.

Matthew Doyle, a former No 10 director of communications, and Katie Martin, a former chief of staff to Rachel Reeves, will be among those appointed to the upper house in a move first reported by the Guardian.

Carol Linforth, a former Labour party chief of staff for operations, and Richard Walker, the executive chair of Iceland and a Labour donor who switched from supporting the Conservatives before the 2024 election, will also receive peerages.

Others on Labour’s list include Michael Barber, a Whitehall veteran who led Tony Blair’s delivery unit and now advises Starmer, and Len Duvall, the chair of the London assembly.

The move brings the number of peers appointed by Starmer to 62. This includes a tranche of 30 peers announced last December and seven who have been created so that they can take up ministerial roles.

The decision is likely to draw criticism from electoral reform campaigners who argue that the appointment process is undemocratic and used by prime ministers to reward their allies.

Labour committed in its manifesto to modernising the Lords by reforming the appointments process, introducing a mandatory retirement age of 80 and ultimately replacing the Lords with “an alternative second chamber that is more representative of the regions and nations”.

Party figures argue that the composition of the Lords needs to be rebalanced in its favour so that the government can push ahead with implementing its legislative agenda.

A Labour source said: “⁠The Tories stuffed the House of Lords, creating a serious imbalance that has allowed them to frustrate our plans to make working families better off. This needs to be corrected to deliver on our mandate from the British people.

“We will continue to progress our programme of reform, which includes removing the right of hereditary peers to sit and vote in the Lords.”

The Lords has been accused of blocking progress in a number of areas in recent months, including government legislation to strengthen renters’ rights, workers’ rights and abolish hereditary peers.

The Conservatives appointed three new peers – the former Conservative MP and head of Margaret Thatcher’s policy unit John Redwood, the gender-critical campaigner and Olympic swimming silver medalist Sharron Davies, and the historian Simon Heffer.

The Liberal Democrats appointed five, including the hereditary peers Dominic Hubbard and John Russell, who had faced removal from the upper chamber as their seats were being abolished.

Reform UK did not appoint any peers, despite writing to Starmer requesting to do so in August.

As of Wednesday the Conservatives have 282 peers, compared with Labour’s 209 and the Liberal Democrats’ 75. There are 177 cross-benchers and 40 non-affiliated peers.

David Cameron created 245 peers during his time in office, 120 of them in his first 18 months, according to the Lords library. Tony Blair created 374, more than any other prime minister, with 101 in his first 18 months.

Boris Johnson created 87 peers despite pledging to shrink the Lords. Theresa May created 43, Rishi Sunak created 51 and Liz Truss, who held power for just 49 days, created 29.