Sir Nicholas Winton's daughter was happy to give permission for her father's life story to be adapted into a film if Sir Anthony Hopkins was cast, One Life’s director has said.

The life story of the British stockbroker who saved hundreds of Jewish children from the Nazis is being adapted into One Life with Sir Anthony taking on the role of Sir Nicholas.

In an interview ahead of the film’s release in UK cinemas on New Year's Day, James Hawes said: "Barbara Winton, Nicky's daughter and biographer, when she gave permission to See-Saw Films to make this project, said 'but you need to cast Anthony Hopkins', which is a pretty big ask, one of the most in-demand actors of his generation.

"So then it was a question of, would Tony respond to the script, and indeed be willing to work with this director?

“And thankfully, yes was the answer to all of those things, and then you had to find an actor who could be the younger him."

Barbara was also a campaigner for refugees and wrote the biography If It's Not Impossible... The Life of Sir Nicholas Winton.

She gave the screenwriting team access to Sir Nicholas's archives and letters before dying last year ahead of the film being finished.

Meanwhile, Johnny Flynn, who is known for roles in Stardust and Emma, will portray Sir Nicholas in his younger years.

Addressing Flynn’s casting to portray a younger Sir Nicholas, Hawes said that Flynn has the same "sort of stockiness and strength" as Sir Anthony.

James Hawes

He added: "He (Johnny) also has a very quiet, generous performance style that we felt would be absolutely sympathetic to what we wanted Tony and Nicky to be and then they talked a lot together.

"Johnny came to the set when Tony was doing the earlier scenes, watched him, sort of reverse-engineered that performance and what the younger version of it would be."

Flynn said: "Barbara Winton died whilst we were filming but she lived to know this story was being made and that was really important.

"Knowing those were the real descendants of the children he saved adds a power, a feeling."

As a young man visiting Prague in the 1930s, Sir Nicholas encountered thousands of Jewish refugees who had fled Nazi-occupied Germany, and he became deeply concerned about the future of the refugee children given the rising threat of a Nazi invasion of Czechoslovakia.

Sir Nicholas spearheaded a team, including his own mother, that organised the evacuation of Czech children, arranging both railway transport, visas and foster families.

Ultimately, he saved 669 children, earning him the nickname ‘the British Schindler’, in a nod to Oskar Schindler, who famously saved 1200 Jewish people during the Second World War.

The story of Sir Nicholas, who died in 2015 at the age of 106, was brought to the wider public's attention by Dame Esther Rantzen in 1988 during a screening of the programme That's Life.