Thomas went on to predict that the royal family could be destroyed by the fallout from his daughter's actions after Meghan and Prince Harry decided to step down as senior royals.
He said: “When they got married they took on an obligation, and the obligation is to be part of the Royals and to represent the Royals.
“And it would be foolish for them not to. This is one of the greatest long-living institutions ever.
“They are destroying it, they are cheapening it, making it shabby. They shouldn’t be doing this."
Thomas also stated that Meghan was "not the girl" he had raised as a child.
After Meghan and Harry's bombshell announcement that they would be stepping back as senior royals, the royal family went into crisis.
And while the news came as somewhat of a shock to everyone in the regal family, including the Queen, no one was reportedly more disappointed than Harry’s dad, Prince Charles.
Charles was apparently one of Meghan’s biggest supporters in the lead up to her nuptials, and since then, their relationship has only got stronger, palace insiders have claimed.
The Duke of Cornwall even walked Meghan down the aisle in her father’s absence, after he apparently persuaded the Queen to allow her to wed Harry.
“He pushed his mother to give his son what he didn’t manage to achieve for himself when he wed Camilla - marrying a divorcee in church,” a friend reportedly told Mail Online.
Charles also supported Harry and Meghan moving into Frogmore Cottage, after the posh residence underwent major renovations, which ended up costing thousands of pounds.
What’s more, Charles is said to have been particularly hurt by the recent events because he was apparently understanding of Meghan’s plight given her very public family drama.
Another source close to Charles reportedly told Mail Online that the drama Meghan had suffered with her own family only “endeared her to him even more”.
“Because there’s been bad behaviour that’s caused problems in his family, Charles understands how difficult it must be for Meghan,” the source claimed.