The father of American actress Meghan Markle says he can’t attend his daughter’s wedding to Britain’s Prince Harry because he needs to undergo heart surgery.

Despite backtracking on his withdrawal earlier this week from the big day and claiming he would “hate the idea of missing one of the greatest moments in history”, Thomas Markle has now told celebrity website TMZ that the plans are off again.

In a procedure scheduled for early on Wednesday night (AEST), doctors “will go in and clear blockage, repair damage and put a stent where it is needed,” he told TMZ. 

Mr Markle, 73, was due to walk his daughter down the aisle at St George’s Chapel, Windsor Castle, in front of 600 guests including all the senior British royals and a smattering of celebrities on Saturday.

But Mr Markle threw the royal wedding plans into confusion earlier this week when he said he would not attend the nuptials because he did not want to embarrass his daughter or the royal family following reports he had staged pictures with a paparazzi photographer for a fee.

He also said he had been in hospital after suffering a heart attack a week ago.

Kensington Palace could not immediately be reached for comment on Tuesday.

In a statement issued on Monday it called Mr Markle’s comments “a deeply personal moment for Ms Markle”.

“She and Prince Harry ask again for understanding and respect to be extended to Mr Markle in this difficult situation,” Kensington Palace said.

The latest report adds to the wedding confusion caused by Mr Markle, who was quoted as saying Tuesday he would not attend the ceremony after a backlash over an alleged $180,000 payment he received for staging photographs with UK tabloid the Mail on Sunday.

The former Hollywood lighting director, who declared bankruptcy in 2016 and now lives in Mexico, told TMZ earlier Wednesday before news of the surgery he believed the photo shoot was a “stupid” move but not a “serious transgression”.

“I don’t think the Queen is thinking about what I’m doing,” he was quoted as saying.

Mr Markle said Meghan tried to call him Tuesday, but has hasn’t spoken to her directly.

He said his daughter “harbours no ill feelings toward him”.

The various changes of heart by Mr Markle days out from their grandson Harry’s wedding – an event that has required military-style organisation for months – has reportedly frustrated the Queen and Prince Philip.

A source told Britain’s Express newspaper that “Her Majesty and the Duke are very angry with Meghan’s father”.

But when she made her first public appearance since the scandal broke, the Queen made it clear it was business as usual ahead of the wedding.

The monarch, 92, hosted her first garden party of 2018 at Buckingham Palace on May 15 and was all smiles.

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As to how Meghan is coping with her father’s health battles and negative publicity, a source familiar with the situation told People magazine, “She doesn’t deserve all this drama the week of her wedding.”

–with AAP