French and German officials have been slammed for politicising the centenary of one of the bloodiest battles of World War One, using the day of remembrance to promote the European Union (EU).

As some 4,000 relatives of those slain in the battle attended a ceremony at Tyne Cot Cemetery, Ypres, the French Embassy jumped on the “opportunity” to credit peace in Europe “brought” by the EU.

Downplaying the part British, Commonwealth, American, and other armies from across the world played in repelling German territorial ambition in the 1914-18 war, the embassy wrote: “Today we commemorate #Passchendaele100. An opportunity to cherish peace, unity and solidarity brought by the EU”, tweeted the official account of the embassy.

Sigmar Gabriel, the German minister for foreign affairs, also shared a tweet about the anniversary, saying: “Today, more than ever, Europe is our future.”

Today we commemorate #Passchendaele100. An opportunity to cherish peace, unity and solidarity brought by the EU: https://t.co/U8cPTiLUo3 pic.twitter.com/sheW7SWuAQ — French Embassy UK (@FranceintheUK) July 31, 2017

Monday marked 100 years since the beginning of the battle of Passchendaele, in Belgium, in which around half a million died.

British and Commonwealth soldiers – from the UK, Ireland, Australia, India, Canada, and across the Empire – advanced across nightmarish, swamp-like conditions on the German line.

Vor 100 Jahren begann bei #Ypern die dritte Flandernschlacht. Heute gilt mehr denn je: Europa ist unsere Zukunft. https://t.co/KbAs0krGJg pic.twitter.com/t39HQ7iVBL — Sigmar Gabriel (@sigmargabriel) July 31, 2017

The EU has been accused of fostering division and even conflict across Europe as the bloc’s political ambitions have grown, and many on the social media platform took offence at the tweets.

User Chris Leigh‏ replied to the French Embassy: “The United Nations was created in 1945 & NATO in 1949, but no, the arrogant EU (1993) asserts that peace is all down to them.”

Gary Watkinson‏ added: “You should apologise for that remark. Deeply offensive to all Allied Forces who gave the ultimate sacrifice.”

Sir Gerald Howarth, a former defence minister, told The Telegraph: “To use Passchendaele and the sombre commemoration of this wanton loss of life as some sort of excuse to justify the European Union is pretty contemptible.”

He added: “The idea that it is the EU who has kept the peace in Europe these past 75 years is nonsense. It has been NATO.

“The implication that Britain’s departure from the EU might render Europe more liable to some sort of European war is also absurd. It suggests we’ve got to remain in the EU in order to contain Germany.”