Emma Thompson once told President Donald Trump to ''f**k off'' when he asked her out.

The 58-year-old actress gave the 71-year-old politician the snub 20 years ago - before he claimed his place in the White House - after he invited her out on a romantic date but she has admitted she was even more baffled by the fact he'd managed to get her number.

Speaking on Britain's 'The Graham Norton Show', which will air on Friday (27.10.17), she said of the President: ''He asked me out once. I could have changed the course of history! I was in my trailer and the phone rang - no one had every rung it nor had I ever used it. I had assumed it didn't work. It was Donald Trump on the other end - I thought someone was having a laugh so told him to f**k off. He said: 'Come and stay in one of my apartments and maybe we could have dinner.' I didn't know what to say.

''I was absolutely astounded because how did he get the number that even I didn't have? I said I would get back to him but I never did.''

But, on reflection, the 'Beauty and the Beast' star wishes she had taken him up on his offer all those years ago because maybe she would have been able to pick his brains and prevent him from winning the US' presidential election in 2016.

She quipped: ''In so many ways I wish I had because I could have ruffled his hair and we would then all have known the truth! And maybe he wouldn't have been president...''