Nadine Dorries berates Rishi Sunak over £3,500 suit and Prada loafers

The Conservative leadership race has descended into fresh acrimony, with the culture secretary, Nadine Dorries, criticising Rishi Sunak for wearing expensive clothes and shoes.

Dorries tweeted newspaper reports that the former chancellor wore a bespoke suit worth £3,500 when he attended a recent leadership vote, and had visited Teesside in Prada loafers worth £450.

She tweeted that by contrast, Liz Truss, the foreign secretary and Sunak’s rival in the Tory leadership race, would be “travelling the country wearing her earrings which cost circa £4.50 from Claire’s Accessories”. A source in Truss’s campaign confirmed the claim.

Angela Richardson, the MP for Guildford and a Sunak supporter, responded to Dorries’ comment by saying: “FFS Nadine! Muted.”

The Cabinet Office minister Johnny Mercer said the leadership contest was embarrassing. He warned that “on current trajectory” the Tory party would be out of power in two years’ time.

“The puerile nature of this leadership contest is embarrassing,” he said. “Time to raise the standards.”

Dorries, who has a lucrative career as a novelist alongside her day job as culture secretary, has previously highlighted her own fondness for bespoke jewellery.

With six weeks to go, the race between Sunak and Truss to succeed Boris Johnson has already been characterised by a bitter briefing war, and repeated clashes over policy and the pair’s records.

In televised debates alongside other candidates, Sunak highlighted the fact that Truss had previously been “both a Liberal Democrat and a remainer” and claimed her plans for unfunded tax cuts were socialist.

Truss contrasted Sunak’s privileged upbringing, attending the costly Winchester College public school, with her own education at a Leeds comprehensive, and claimed his tax policies risked pushing the UK into a recession.

Sunak and his wife, Akshata Murty, have considerable personal wealth, with her share in the Indian tech firm her father founded estimated to be worth £700m alone.

She agreed to pay UK tax on her worldwide earnings earlier this year after a backlash over the fact she was claiming non-dom status, a longstanding tax loophole Labour has said it would abolish.

Sunak has been photographed repeatedly wearing costly clothes and accessories: official photos of him preparing for last year’s budget showed him in £95 sandals (with socks) from the California brand Palm Angels; while he was previously shown holding a £180 “smart mug”.

Over the weekend, Truss and Sunak competed to take the most hardline approach on immigration, in an effort to win over wavering Tory members.

Despite proudly pointing to his own background as the grandson of immigrants, Sunak has said he would cap the number of refugees the UK would accept – a move that appears to be illegal under international law – and house failed asylum-seekers on disused cruise ships.

Truss has suggested she would negotiate further deals like that under which Rwanda is preparing to accept refugees from the UK, and increase the size of the UK’s Border Force.

The candidates have also clashed over China, with Sunak saying he would crack down on links to the communist state, including by closing the Confucius Institutes opened at a series of UK universities in recent years.

While Sunak’s team suggested Truss had failed to act against Chinese influence on the UK’s higher education institutions when she was an education minister, her allies shot back that he had been keen to strengthen economic ties with Beijing while chancellor.