The Duke of Sussex is to join the Duchess of Cambridge at the Anzac Day service in Westminster Abbey.

Buckingham Palace confirmed Harry, whose first child is due any day now, would gather with his sister-in-law Kate on Thursday afternoon to honour the sacrifices of Australian and New Zealand forces.

Harry’s last-minute addition to the royal line-up indicates Meghan is showing no signs so far of giving birth soon, with the duke able to leave his wife to attend the hour-long memorial in central London.

American former actress Meghan is likely to be at home in the couple’s newly renovated Frogmore Cottage in the sanctuary of the Windsor Estate.

Harry and Meghan
Harry and Meghan, who is due to give birth in the coming days (Dominic Lipinski/PA)

Harry and Kate will be joined by the Queen’s cousin the Duke of Gloucester, for the annual Anzac Day Service of Commemoration and Thanksgiving.

Meanwhile the Duke of Cambridge is in New Zealand where he paid tribute to those who lost their lives in battle by attending a service in Auckland.

Anzac Day – April 25 – marks the anniversary of the start of the First World War Gallipoli landings, and is a national day of remembrance for Australia and New Zealand.

William in New Zealand
The Duke of Cambridge places a wreath at the Auckland Anzac Day Civic Service (Mark Tantrum/New Zealand Government/PA)

The traditional church service in London will incorporate an Act of Remembrance, the Last Post and the words of modern Turkey’s founder Kemal Ataturk from Anzac Cove, read by the Turkish ambassador to the UK.

Thousands of Anzac troops – Australian and New Zealand Army Corps – died in the ill-fated 1915 campaign.

Waves of Allied forces launched an amphibious attack on the strategically important Turkish peninsula, which was key to controlling the Dardanelles straits, the crucial route to the Black Sea and Russia.

But the plan backed by Winston Churchill, then first lord of the admiralty, was flawed and the campaign, which faced a heroic defence by the Turks, led to stalemate and withdrawal eight months later.

Its legacy is the celebration of the “Anzac spirit” – courage, endurance, initiative, discipline and mateship – shown by the Antipodean troops.