Prince Harry is likely to include marigolds when he lays a wreath at the Cenotaph on Armistice Day on Sunday as a tribute to 1.5 million Indian soldiers who fought for Britain in World War I.

The Duke of Sussex said he realised this gesture would not please everyone.

Harry’s comment came as he honoured Britain’s war dead at a ceremony to open Westminster Abbey’s Field of Remembrance, which marks its 90th anniversary this year.

On Sunday Harry will join the Prince of Wales, the Prime Minister, cabinet members and other national figures laying wreaths at the Cenotaph.

The duke, a former army officer, stopped at one of the 370 plots in the shadow of the Abbey, representing regiments, military organisations and other bodies and covered with tiny wooden crosses, to chat to Suraj Samant, 23, from the Hindu Council UK.

Samant, who handed Harry a marigold, said his plot represented India’s World War I forces. He said after their meeting: “His elder brother and his father both put a wreath of marigolds down at India Gate at New Delhi to commemorate (India’s fallen) so I thought it was poignant to also offer His Royal Highness a marigold as part of the Indian diaspora’s centenary commemorations.”

He said 74,000 Indians were killed during the conflict.

Samant added: “His Royal Highness spoke of the sacrifice, and said his father had expressed that to him in great detail, and to remember that sacrifice, and it’s very necessary to mark that here.

“He said he’d add a couple of marigolds into his wreath that he puts down at the Cenotaph if he had the choice. I think he recognises that sacrifice himself.” Samant added that Harry said if he made the gesture recognising India’s fallen, it would not please everyone.