Business Secretary Kwasi Kwarteng claimed “even the Prince of Wales was interested” in the Tory leadership election as he mingled at a drinks reception at Buckingham Palace.

Mr Kwarteng was attending the event hosted by Charles for recipients of The Queen’s Awards for Enterprise at the palace on Tuesday night.

The Conservative MP was among a line of people who greeted Charles as he arrived, and as they chatted Mr Kwarteng appeared to say: “It’s kicking off.”

Asked about the exchange later on, Mr Kwarteng told the PA news agency: “It’s kicking off, the leadership, even the Prince of Wales is interested in the Tory leadership.

“We do this every three years – but there you go.”

His comments come after Boris Johnson resigned as Conservative Party leader last week, triggering a contest to replace him in Number 10.

The Queen’s Awards for Enterprise recognises firms’ achievements in innovation, international trade, sustainable development and promoting opportunity through social mobility.

Despite the sweltering temperatures, Charles wore a suit as he mingled with award-winners at the reception, which the Princess Royal also attended.

Mr Kwarteng said of the event: “It’s fabulous, we’ve got brilliant businesses from all over the country and we are celebrating the best of what this country can do.

“We’re really celebrating the best of British business.”

The Prime Minister recommends winners to the Queen, and the Department for Business, Energy and Industrial Strategy then announces them on April 21 each year.

Winning organisations receive a grant of appointment and a trophy and can display the award emblem for up to five years.

This year there are 232 Queen’s award winners, including seven double award winners, selected from 777 applications.

A breakdown of 2022’s winners by category shows there were 141 gongs for international trade, 51 for innovation, 31 for sustainable development and nine for promoting opportunity.

Among the recipients was Piran Littleton, managing director of Jesmonite, who said: “As a business we make posh concrete and plaster, so it’s an eco-friendly, water-based, lightweight concrete and plaster.

“We make the powders and liquids and then people turn it into beautiful things.

“It has been used in Buckingham Palace, Poundbury (Charles’ estate in Dorchester, Dorset) and then it gets used in James Bond films and the arts and crafts market.”

On meeting Charles, he added: “We spoke about Poundbury because it has been used on the Royal Pavilion on making the columns there and he was saying he hoped that Poundbury would be close to being finished soon.”

Shirine Khoury-Haq, interim chief executive of the Co-op Group, which won an award for sustainable development, said she discussed the rising cost of living and energy costs with Charles.

She said: “We actually spoke about the cost-of-living crisis and the impact that is having on people.”