Prince Charles will walk Meghan Markle down the aisle when she marries his son Prince Harry.

He will step in for the father of the bride, Thomas Markle, who is unable to attend the day because of heart problems.

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Eastern Daily Press: Prince Harry and Meghan Markle. Picture: PA Wire/PA Images.Prince Harry and Meghan Markle. Picture: PA Wire/PA Images. (Image: PA Wire/PA Images)

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Kensington Palace announced that Charles would give his soon-to-be daughter-in-law away when she marries Prince Harry tomorrow in the historic surroundings of St George's Chapel, Windsor Castle.

The palace said the American former actress had asked her future father-in-law to accompany her as she makes her way to the altar.

In statement, Kensington Palace said: 'Ms Meghan Markle has asked His Royal Highness The Prince of Wales to accompany her down the aisle of the Quire of St George's Chapel on her Wedding Day.

'The Prince of Wales is pleased to be able to welcome Ms Markle to The Royal Family in this way.'

Meghan's father Thomas Markle was forced to pull out of performing the fatherly duty after undergoing heart surgery in a dramatic upset just two days before the wedding.

The star's mother Doria Ragland had been tipped to perform the role.

But unlike Ms Ragland, Harry's father is vastly experienced at appearing at large-scale public events amid intense scrutiny.

He also performed the duty for Alexandra Knatchbull, the daughter of his close friend, Lord Brabourne, in 2016.

It is understood that Harry was involved in discussions with his fiancee about who should take on the important role on the big day.