"He wants to protect her and this is really hard for him to swallow".
"He feels like this is another thing in the wake of him. the problems he causes. They photograph you as unflattering ways as they can", she said.
Thomas Markle initially said on Monday that he was backing out of walking his daughter down the aisle at her wedding to Prince Harry because he didn't want to embarrass her following his staged paparazzi photos debacle.
The 61-year-old is now expected to step into her ex-husband's shoes and walk her daughter down the aisle if he is missing from the ceremony.
Markle, 36, has not responded to the scandal directly, but the palace pleaded for privacy.More news: Incognito mode may be coming to the YouTube app
Both parents were also expected to meet Queen Elizabeth II and other senior royals in the days before the wedding. "Ever since Meg's relationship with Harry was made public two years ago, we have lived our once normal lives under the spotlight every second", he told the Daily Mail.
Just days before the wedding, the British media outlet Mail on Sunday reported the 73-year-old father of the bride posed for a photographer at an internet cafe in Rosarito, Mexico, where he now lives. Markle told the website he looked "stupid and hammy".
This all comes after a Mail on Sunday report featured CCTV footage of what appeared to be Thomas arranging to take paparazzi images with a photographer.
It was on an episode of General Hospital that Ms Markle made her television debut in 2002.
Mr Markle reportedly added that since his daughter started dating Prince Harry he had been offered between $50,000 and $100,000 for interviews but he'd turned all of them down.
The Mail on Sunday, a British media outlet, published photos and a surveillance video that it claims show Markle Sr., a former lighting director in Hollywood, staging photos in Rosarito, Mexico, where he now lives.
She is not on the wedding guest list.More news: Sherpa guides scale Everest to pave way for others climbers
Ms Markle's half-sister Samantha Markle attempted to shoulder some of the blame when she earlier tweeted it was her idea for Mr Markle to pose for what she described as "positive photos" in a bid to combat his "bad" portrayal in the press, but stated it was not done for money.
Mr Markle is also reported to have suffered a heart attack in recent days.
"It is overwhelming. My grandfather just wants to be left alone - he wants the peace and the quiet back". He says the doctors told him his heart was "seriously damaged" after his heart attack a week ago. But if he did, I am going to assume it was a pittance - they don't pay that much.
"Everyone needs to pause and think what this is doing to them and, more importantly, to him".
The palace had announced last week that Thomas Markle and his ex-wife, Doria Ragland, would play important roles in the wedding. That is his daughter and she loves him more than anything in the world. Originally, he was supposed to walk Prince Harry's bride down the aisle. (Supplied) Harry and Meghan have have called for understanding.More news: Iran says USA sanctions derail nuclear deal