Thomas Markle threatens legal action to see Harry and Meghan's children

Thomas Markle has slammed Meghan and Harry yet again. Photo / 60 Minutes

Meghan Markle's estranged father Thomas Markle wants to see his grandchildren - and has threatened legal action to make sure that happens.

The Duchess' father says he is ready to take the fight to court, in order to finally meet Archie and Lilibet Diana.

In a video obtained by Fox News, the grandfather, a former Hollywood lighting director, accuses Harry and Meghan of using the children as "pawns".

Meghan, Duchess of Sussex on October 25, 2018 in Nadi, Fiji. Photo / Getty Images

"We shouldn't be punishing [Lili] for Meghan and Harry's bad behaviour," he said, quoted by Fox News.

"Archie and Lili are small children. They're not politics. They're not pawns. They're not part of the game. And they're also royal and entitled to the same rights as any other royal."

Thomas Markle, pictured with a young Meghan, staged paparazzi photos in the lead-up to the 2018 royal wedding. Photo / Supplied

Markle added that he "will be petitioning the California courts for the rights to see my grandchildren in the very near future".

During the video, he also took the opportunity to slam Prince Harry's recent announcement that he is working on his memoir, to be released next year.

"Harry doesn't have too much more to tell," he said.

"After three sessions with the psychiatrists and Oprah Winfrey, I don't know what more is there to tell."

When contacted by Fox News, a spokesperson for the Duke and Duchess of Sussex said that "this is not something they would comment on".