Labour has accused Rishi Sunak of a “dereliction of duty” after he gave a TV interview about the election while missing a major international ceremony to mark the 80th anniversary of D-Day.

The Prime Minister sat down with ITV on Thursday to defend claims he had made about Sir Keir Starmer’s tax plans, having left commemoration events in France before a gathering of the world leaders on Omaha Beach.

He had appeared in Normandy earlier in the day to pay tribute to veterans but returned to Britain before the ceremony was over, while his rival Sir Keir remained alongside Joe Biden, Emmanuel Macron and the Prince of Wales.

It later emerged that Mr Sunak had given a broadcast interview on the same day, a clip of which was shared by broadcaster Paul Brand.

Mr Brand told ITV News at Ten: “Today was the slot we were offered … we don’t know why.”

Shadow paymaster general 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.

“Our country deserves so much better than out-of-touch, desperate Rishi Sunak and his chaotic Tory Party.”

The Conservative Party has been contacted for comment.

Political cut and thrust had largely been paused on Thursday morning as the 80th anniversary of D-Day took centre stage, and Mr Sunak appeared in his prime ministerial capacity at various commemoration events.

Tory sources had played down the diplomatic impact of the PM’s absence in Normandy later in the day, pointing out he will be meeting other G7 leaders next week at a summit in Italy.

Mr Sunak had used his interview with Mr Brand to reject Labour accusations that he “lied” by saying the party would hike taxes by £2,000 – claims which were later criticised by the UK statistics watchdog.

D-Day 80th anniversary
Labour Party leader Sir Keir Starmer speaks with First Minister of Scotland John Swinney  at the UK’s national commemorative event for the 80th anniversary of D-Day (Dylan Martinez/PA)

The Prime Minister said the Labour leader was “obviously very rattled” after he repeatedly deployed the attack line during a TV election debate earlier this week.

Mr Sunak had claimed that “independent Treasury officials” have costed Labour’s policies “and they amount to a £2,000 tax rise for everyone”.

But the Treasury’s permanent secretary James Bowler said ministers had been told not to suggest civil servants produced the figure.

In the interview, the Prime Minister said: “Keir Starmer and the Labour Party are obviously very rattled that we’ve exposed their plans to raise tax on people. And that’s what it, that’s what it demonstrates.”

Asked whether the numbers were instead based on assumptions drawn up by Tory advisers, Mr Sunak said: “No. The analysis and the working is done by Treasury officials.”

The row stems from a document produced by the Conservatives which made a series of assumptions to estimate the cost that might be attached to potential Labour policies.

It said that Labour’s plans had a £38.5 billion deficit over four years, the equivalent of £2,094 for every working household, which the Tories claim would be filled with tax hikes.

In a statement on Thursday, the UK statistics watchdog, which previously warned political parties to use figures appropriately during the campaign, suggested the Conservatives had failed to make clear their calculations.

The Office for Statistics Regulation said: “Without reading the full Conservative Party costing document, someone hearing the claim would have no way of knowing that this is an estimate summed together over four years.”

Campaigning for the General Election will kick off again in full on Friday, with the Prime Minister out in the south west promoting the latest Tory pledge to raise the high-income child benefit tax charge threshold to £120,000.

Meanwhile, Labour is promising that first-time buyers could use the state as a guarantor for their mortgages if it wins the July 4 vote.