Thomas Markle has warned that ‘everything will come out’ if he faces daughter Meghan in court.
The Duchess of Sussex is suing a newspaper for publishing a personal letter she sent to him in August 2018.
Mr Markle has already agreed to be a witness and pledged to expose what he said were ‘lies’ about him.
‘It will be emotional. I don’t know how we will both accept it,’ he said.
‘It would be the worst place to have to meet her and Harry – but it might come down to that because I will certainly testify against the things that have been said about me. The lies.’
Thomas Markle, appearing in a Channel 5 documentary that aired last week, has warned that ‘everything will come out’ if he faces daughter Meghan in court
Mr Markle also called the Sussexes’ decision to step back from their duties the ‘dumbest thing’.
Labelling Prince Harry ‘whipped’, he also told the Sun his daughter ‘has turned into his mother’.
The two have not spoken since the fall out before the Royal wedding in 2018, with Mr Markle yet to meet Prince Harry or grandson Archie.
He revealed he had gone to the Mail on Sunday – the sister paper of the Daily Mail – about the infamous letter in order to defend himself from attacks from Meghan’s friends in People magazine.
Meghan, 38, has accused the newspaper of breaching her privacy, her data protection rights and her copyright when it published extracts.
The 75-year-old has already given lawyers previously unseen text messages that reveal the breakdown of the relationship between father and daughter.
Mr Markle also called the Sussexes’ (pictured) decision to step back from their duties the ‘dumbest thing’
Mr Markle added: ‘I’m tired of being lied about and not being defended.
‘I put the newspaper in this position by offering up a portion of that letter, which led to them being sued.
‘This is my fault so I have to stand up for myself. It is a responsibility thing.’
In the letter, Meghan allegedly accused her father of breaking her heart ‘into a million pieces’ and causing her to ‘crumble inside’ by colluding with a paparazzi photographer.
Mr Markle, however, said the Sussexes had done ‘exactly what they told me I shouldn’t be doing’ by stepping back.
He added: ‘They are cashing in on the Sussex name.
‘They’ve gone commercial. They should be just called Harry and Meghan now.
Mr Markle showing some royal souvenirs he keeps on the mantle of his home during the Channel 5 documentary that aired last week
‘Leaving the Royal Family is the dumbest thing they could have done.
‘I don’t think they thought this out. It’s almost an abdication.
‘The only thing I can say is there are people who say she was reaching out to me and saying she loved me.
‘Well the word ‘love’ is not there at all, in relation to me.’
Earlier this month half-sister Samantha revealed her father was ‘deeply hurt’ by the letter, telling the BBC: ‘If he is called, he will come.’
However, Mr Markle revealed it won’t be easy to testify due to the love he still holds for Meghan, but admitted it was his responsibility.
He said: ‘It would definitely be a two-Valium day for me.
‘My nerves would be going, my stress levels would be very high and my blood pressure up.
‘If I saw her, I would say: ‘I’m sorry, I wish we could have sat down and worked this out’.
Thomas Markle has shared his family album with Channel 5 including this picture of him bonding with Newborn Meghan as she changed her nappy after her birth in August 1981
‘I don’t like the idea of sides, of being in a battle with my daughter. I don’t like not being able to talk to her.
‘But in a way I would be thrilled to meet her, wherever she shows up. Although that (a court) is not the ideal place. I love my daughter. I think I have made that clear to everybody.
‘It hurts we couldn’t find a way to make up. All I want to do is tell the truth.’
The latest revelation from Mr Markle comes just a few days after he appeared in a bombshell documentary charting the relationship with his daughter.
The 75-year-old shared extraordinary unseen photos and films of his Duchess daughter for the Channel 5 film where he spoke of their loving and close relationship
He also described his pride after the birth of his daughter in August 1981 as he opened up to Britain’s Channel 5 in a film, watched by 1.2million people last week – just days after the Duke and Duchess of Sussex started their new life in Canada.
Meghan sits up on her parents’ bed in another a new family photo shown on the Channel 5 documentary
Mr Markle says Meghan’s childhood years were ‘the happiest of my life’ as he shared dozens of pictures of her key moments including on the day she entered the world and as father and daughter bonded while he changed her nappies in the following days.
There are also a string of happy photos of Meghan with her mother Doria Ragland, including at family Christmas parties and summer picnics near their home in California, before she moved in with Thomas as a teenager after the couple’s divorce.
Mr Markle has also shared rare home video footage of Meghan’s first school productions where he says a star was born, her high school graduation and leaving for college.
An emotional Mr Markle also said he was ‘jealous’ and cried as he saw the Prince of Wales walking his daughter down the aisle and justified making the film to defend himself and rebut the ‘trashy things’ said about him.