The formerly Conservative-supporting boss of the supermarket Iceland is to be made a Labour peer when the party appoints another 25 representatives to parliament’s upper house later this month.

Keir Starmer will appoint Richard Walker to the House of Lords, the Guardian understands, the culmination of an unusual and rapid political transformation for someone named as a prospective Tory MP candidate a little over three years ago.

It was only February this year when Iceland’s executive chair was rating Starmer’s government six out of 10, saying that Labour needed to focus on “inclusive growth and everyday growth” that could “trickle down in everyday people’s lives”.

As a Labour peer, Walker will get the chance to push for policies close to his heart including closer relations with the EU and also for a more positive message on the economy.

He took over the leadership of Iceland in 2023 after his father, Malcolm Walker, stepped down from the frozen foods chain he had founded in 1973. Both men have previously expressed support for the Conservative party and have donated money to it.

Richard Walker donated nearly £10,000 in July 2020, when Boris Johnson was prime minister during the Covid pandemic. He was then added to a list of approved parliamentary candidates for the party in 2022, only to perform an abrupt about-turn the following year.

Writing in the Guardian in 2023, Walker said the Conservatives had “drifted badly out of touch with business and the economy, and with the everyday needs of the British people”.

He then backed Keir Starmer in early 2024, saying that “after a lot of soul-searching” he had decided he had “exactly what it takes to be a great leader”. Walker’s comments did not, however, suggest a would-be Labour politician. He said the Tories’ abandonment of “basic Conservative principles” had added to his disenchantment.

Nevertheless, his appointment as a Labour peer, first reported by the Sun, would add a rare business voice in support of Starmer’s government, which has irked several sectors by raising national insurance. The Conservative party counts another retail boss, Simon Wolfson of Next, among its peers.

Some bosses have also complained about increases to business rates paid on commercial properties introduced at last month’s budget. Some large retail businesses, however, expressed relief at the fact the changes were less onerous than expected.

The Labour party declined to comment. Walker was approached for comment.