The department passed on two messages to Downing Street in the weeks leading up to the event, which were then ignored, leading to the worst election campaign blunder of the last 14 years.
The claim is contained in Blue Murder, by the Daily Telegraph's political editor, Ben Riley-Smith.
The Guardian has also spoken to sources about that day's events.
According to the book, the Foreign Office provided written advice on two occasions before the event telling Downing Street that the prime minister should attend.
The first came a few weeks before the event and the second just a few days before, once it became clear that Keir Starmer would be attending, as would the Ukrainian president, Volodymyr Zelenskiy.
One source spoke of "very clear advice from the department that it would be an important event to go to and there would be significant risks should he not attend".
Having endured a difficult start to the campaign, Sunak had regained some momentum with a combative first debate performance against Starmer. But as the 80th anniversary D-day commemoration approached on 6 June, his senior team had no sense of the PR disaster about to engulf them.
Diese Geschichte stammt aus der August 27, 2024-Ausgabe von The Guardian.
Starten Sie Ihre 7-tägige kostenlose Testversion von Magzter GOLD, um auf Tausende kuratierte Premium-Storys sowie über 8.000 Zeitschriften und Zeitungen zuzugreifen.
Bereits Abonnent ? Anmelden
Diese Geschichte stammt aus der August 27, 2024-Ausgabe von The Guardian.
Starten Sie Ihre 7-tägige kostenlose Testversion von Magzter GOLD, um auf Tausende kuratierte Premium-Storys sowie über 8.000 Zeitschriften und Zeitungen zuzugreifen.
Bereits Abonnent? Anmelden
Scientists develop 'vaccine' to protect bees from pesticides
Scientists have developed a \"vaccine\" for bees against pesticides - and it appears to work, according to an initial study.
Jewish Chronicle IDF inquiry into claims of stories planted for disinformation campaign
The Israel Defense Forces have launched an investigation into allegations in the Israeli media that the London-based Jewish Chronicle published stories based on \"fabricated intelligence\" relating to Hamas, amid claims they may have been planted as part of a disinformation campaign.
'He is far away in Saudi' Ten Hag brushes off Ronaldo's attack over lack of ambition
Erik ten Hag has hit back at Cristiano Ronaldo by pointing out that the Portuguese admitted Manchester United are not well placed to win the biggest trophies this season despite criticising the manager for stating the same.
So much about the Ballon d'Or suggests that it does not care about women's football
The release of the Ballon d'Or shortlists naturally focused on the absence of Lionel Messi and Cristiano Ronaldo from the men's top 30 for the first time in 21 years, yet the real glaring omissions were to be found among the awards ceremony's token efforts regarding women's football.
Vaughan and Leach shock Surrey to set up title chase
The County Championship title race has been blown wide open after Somerset snatched a dramatic victory over the leaders, Surrey, with a couple of minutes to spare at Taunton, the champions' stout defensive rearguard toppled after they collapsed from 95 for three to 109 all out in a final hour overflowing with tension.
Pettersen backs Hull to light up the course
But captain causes a surprise by omitting Solheim Cup specialist Maguire from today's opening foursomes
Stellantis halts production of Fiat 500 EV for four weeks due to slowdown in European sales
Stellantis said yesterday it would halt production of the electric Fiat 500 model for four weeks owing to a lack of orders in Europe.
Grangemouth oil refinery to shut and become fuel import terminal with 500 jobs at risk
The owners of the Grangemouth oil refinery confirmed yesterday it would shut by the end of June in a blow to Scotland's industrial base and the site's 500 employees.
Refugees Spanish FC leads town's welcome
They filed on to the football pitch as applause rang out, punctuated by shouts of bienvenidos.
Harris heads to swing states buoyed by debate performance
Kamala Harris embarked on a drive to exploit her strong debate performance yesterday, as the Democratic presidential nominee's campaign pledged to intensify efforts to persuade voters in battleground states deemed essential to winning the White House.