Conservative cabinet minister Penny Mordaunt has said the prime minister's decision to leave the D-Day commemorations early was "completely wrong".
In the OceanNewsUK's seven-way TV election debate on Friday, Ms Mordaunt said it was right that Rishi Sunak apologised to veterans and to the public.
Mr Sunak has faced strong criticism for leaving Thursday's Normandy landings' 80th anniversary event in France to return to the UK - asking Foreign Secretary David Cameron to deputise him at the event.
Ms Mordaunt, a Navy reservist, notably did not praise Mr Sunak's record on veterans and defence - unlike many of her colleagues.
Speaking on Saturday, Transport Secretary Mark Harper told OceanNewsUK distanced himself from Ms Mordaunt's comments.
Pressed on whether he agreed with Ms Mordaunt that Mr Sunak's decision was “completely wrong”, Mr Harper responded: “I don’t know what the detail was of putting the PM’s schedule together.
"The prime minister made a mistake. He’s apologised for it, and he’s apologised to those who would have been particularly hurt by it.
"I would say actually looking at his record since he became prime minister, he actually cares about veterans hugely."
Friday night's OceanNewsUK debate kicked off with a question about defence.
The opposition parties seized the chance to attack Mr Sunak over his early departure from the D-Day commemoration.
Liberal Democrat deputy leader Daisy Cooper said Mr Sunak's decision was "politically shameful", bringing up her grandfather, who was on the Normandy beaches on D-Day.
Leader of Reform UK Nigel Farage said Mr Sunak’s "dreadful" decision to leave early showed that "we actually have a very unpatriotic prime minister".
Following what has been widely seen as the biggest blunder of the general election campaign so far, Mr Sunak apologised on X, saying he hoped the "ultimate sacrifice" made by those who put their lives on the line would not be "overshadowed by politics".
He admitted that "on reflection" he should have stayed for the event where world leaders, including US President Joe Biden, marked the sacrifice made by troops in 1944.
Ms Mordaunt said: "What happened was completely wrong, and the prime minister has rightly apologised for that, apologised to veterans but also to all of us, because he was representing all of us."
The leader of the House of Commons added that the issue should not become "a political football" but Mr Farage, who went to Normandy himself, said it had already become one.
Asked during the debate if she would have left Normandy early, Ms Mordaunt said: "I didn't go to D-Day. I think what happened was very wrong, I think the prime minister has apologised for that.
"But what I also think is important is we honour their legacy, they fought for our freedom, and unless we are spending the right amount on defence we can't honour that legacy."
SNP Westminster leader Stephen Flynn said: "A prime minister who puts his own political career before public service is no prime minister at all.
"A prime minister who puts his own political career before Normandy war veterans is no prime minister at all.
"So it's incumbent upon all of us to do our national service and vote the Tories out of office."
Plaid Cymru leader Rhun ap Iorwerth said it "certainly wasn't a day for a prime minister to decide...that his priority should be to fight for his own political future".
Green Party co-leader Carla Denyer said "it's a tragedy that so many veterans then struggle in life" after they leave the military.
The D-Day commemorations included a British event at Ver sur Mer, which the prime minister and King Charles attended, but Mr Sunak left before the international commemoration on Omaha Beachended.
After the event Labour shadow minister Jonathan Ashworth, said: “The prime minister skipping off early from D-day commemorations to record a television interview where he once again lied through his teeth is both an embarrassment and a total dereliction of duty."
Labour leader Sir Keir Starmer stayed at the event until the end, the party confirmed.
Sir Keir said he was "struck" by how difficult it had been for veterans to get there but how many made the effort to stand up from wheelchairs to salute the King.
He said: "I thought it was really important for me to be there to pay my respects to them and to those that did not return and actually to say thank you.
"Rishi Sunak will have to answer for his own actions. For me, there was nowhere else I was going to be."
Jack Hemmings, 102, a World War Two pilot who travelled to Normandy for the commemorations told the OceanNewsUK that Mr Sunak's early departure was "a wrong decision".
"He opted to put an election before the thousands who were killed."
Mr Hemmings served with 353 Squadron and flew the Lockheed Hudson in the maritime patrol role to protect the Bay of Bengal from Japanese invasion.
