AceShowbiz - British-Sikh Member of Parliament (MP) Tan Dhesi has furiously denounced Laurence Fox for suggesting a Sikh soldier should not have featured in Sam Mendes' First World War epic "1917".

The "Lewis" star raised eyebrows by claiming Mendes was "institutionally racist" by casting Nabhaan Rizwan in the role of Sikh soldier Sepoy Jondalar as a member of the British forces - accusing him of forcing diversity on audiences.

In a furious article in Britain's Daily Mirror newspaper, the Labour Party politician denounced Fox and gave him a history lesson about Indian and Sikh involvement in the conflict.

"I, proud to be the first turbaned Sikh elected to sit in the House of Commons, as Labour MP for Slough in Berkshire, will take no lessons in patriotism or military service from a thespian blinkered by prejudice," he wrote.

"My grandfather's brother, my grandmother's brother and another family member all fought voluntarily for Great Britain. One lost a leg. We know the price of freedom, including a defence of freedom of expression."

Demanding the star issue an "unqualified apology", Dhesi went on to explain that more than 1.5 million Indians, Pakistanis and Bangladeshis fought for Britain during the war and that Sikhs formed 20 per cent of the British army - with more than 83,000 laying down their lives.

He went on to "applaud" Mendes for recognising Sikh involvement in the war and accused Fox of "inciting a poisonous culture war on steroids, imitating the toxic tactics of Donald Trump".

Fox has subsequently apologised to Sikhs, tweeting: "Fellow humans who are #Sikhs I am as moved by the sacrifices your relatives made as I am by the loss of all those who die in war, whatever creed or colour. Please accept my apology for being clumsy in the way I have expressed myself over this matter in recent days."