In a new clip from the upcoming Channel 5 documentary (obtained by SkyNews), Thomas aggressively criticizes his daughter's decision to leave the royal family less than two years after her royal wedding.
"With Meghan and Harry and separating from the royals, I've already said it's disappointing to me," Thomas says in the clip. "It's disappointing because she actually got every girl's dream. Every young girl wanted to become a princess and she got that and now she's tossing that away for, it looks like she's tossing that away for money."
Calling the couple's decision "embarrassing to me," Thomas continues to throw shade, adding, "Apparently $3 million and a 26-bedroom home isn't enough for you. I don't know. I can't go much further than that."
"They are destroying it, they are cheapening it, making it shabby - they are turning it into a Walmart with a crown on it now."
Meghan's father has criticised the couple's decision to step back from the Royal Family.
Thomas, who has spoken out against his daughter several times since her 2018 wedding, also notes that Meghan "took on an obligation," calling the decision to step back "foolish."
"This is one of the greatest long-living institutions ever. They're destroying it," he says. "They're cheapening it. They're making it shabby. They're turning it into a Walmart with a crown on it now. It's something that's ridiculous. They shouldn't be doing this."
Thomas, who has not spoken to his daughter in months, doesn't see them reconciling anytime soon.
"I can't see her reaching out to me, especially now in light of what I'm saying now," he admits. "She probably won't, or Harry for that matter. I think both of them are turning into lost souls at this point. I don't know what they're looking for. I don't think they know what they're looking for."
Meghan's relationship with her father has been estranged for months. He was set to walk her down the aisle in 2018, but cancelled at the last minute due to heart issues. He has since been the subject of tabloid news and is at the center of Meghan and Harry's lawsuit with the British media after The Mail on Sunday published a private, handwritten letter from the duchess to her father.
On Saturday, Queen Elizabeth II announced the final decision from Buckingham Palace regarding the Duke and Duchess of Sussex's futures. In a statement, the Queen revealed that the couple will lose their HRH titles and will repay the money they used to refurbish their Frogmore Cottage home in Windsor, England.
"I want to thank them for all their dedicated work across this country, the Commonwealth and beyond, and am particularly proud of how Meghan has so quickly become one of the family," Queen Elizabeth said in the statement. "It is my whole family’s hope that today’s agreement allows them to start building a happy and peaceful new life."
The Palace also noted that the couple will no longer be working members of the royal family, though they would not comment on security measures surrounding the couple's future. This decision comes just over a week after Harry and Meghan announced their plan to step back as senior members of the royal family, to become financially independent, and to split their time between North America and the U.K.