Rishi Sunak has apologised for leaving D-day anniversary events early to take part in a TV interview, admitting it was “a mistake not to stay in France longer”.

The prime minister had been heavily criticised for allowing the foreign secretary, David Cameron, to take his place in the late afternoon ceremony at Omaha beach on Thursday, while he left Normandy to do a prerecorded ITV segment to be broadcast next week.

On Friday, the prime minister said on X: “I care deeply about veterans and have been honoured to represent the UK at a number of events in Portsmouth and France over the past two days and to meet those who fought so bravely.

“After the conclusion of the British event in Normandy, I returned back to the UK. On reflection, it was a mistake not to stay in France longer – and I apologise.”

Conservative activists reacted with fury at the sight of Cameron standing alongside the French, German and US leaders, Emmanuel Macron, Olaf Scholz and Joe Biden, with one saying it had left them questioning whether to “bother to continue campaigning”.