Mattinson (pictured) co-founded BritainThinks (now Thinks Insight & Strategy) in 2010, working at the company until leaving in 2021 to work for Sir Keir Starmer after his election as Labour party leader until departing the role after the 2024 general election.

Prior to setting up BritainThinks, Mattinson worked for former UK prime minister Gordon Brown, and had worked as an advisor to the Labour party since the 1980s.

Mattinson is also the author of Beyond the Red Wall, a book published in 2020 covering why Labour had lost support in its traditional post-industrial heartlands.

In a statement posted to social media, Mattinson said: “I’m thrilled and honoured to be asked by the Prime Minister to serve in the House of Lords.

“I’m very much looking forward to supporting the government to bring his Plan for Change to life and work towards a fairer, more prosperous Britain.”

Mattinson was among 30 peers appointed by Labour, alongside six Conservatives and two Liberal Democrats.

Other prominent appointments to the House of Lords include former shadow culture secretary Thangam Debbonaire, British Council vice-chair Wendy Alexander, former first minister of Wales Carwyn Jones, former Labour chief of staff Sue Gray and former deputy prime minister Thérèse Coffey.