The children rescued by Sir Nicholas Winton‘s Kindertransport as the world was on the brink of war are pensioners now, but their gratitude to the “unassuming” hero has not waned down through the decades.

Generations were able to live because of his bravery and those attending the London service in his honour say they “owe everything” to him.

Many were able to meet him when the story of what he had done in 1939 was brought to public attention, and they described him as a modest man who did not want to make a fuss despite the enormity of his actions.

Renate Collins, who now lives in Caldicot near Chepstow in Wales, said she hoped Sir Nicholas realised how “incredibly appreciated” he was.

The 82-year-old was aged five when she left Prague on one of the trains, and later found that 64 members of her family perished in the Holocaust.

She recalled an event a number of years ago which she attended with her sons who, when they realised Sir Nicholas was present suddenly “disappeared”.

They later told her: “Mum, we had to go out and thank Sir Nicholas – shake his hand and thank him for saving our mother.”

Kurt Taussig, whose entire family aside from two brothers died, said he and the other 668 children owed Sir Nicholas everything.

The 92-year-old, who lives in Stanmore in north-west London, will attend the service with his son.

He said: “It’s one thing I wouldn’t miss for anything because we owe everything to him – myself, my family, my children, everything.”

He said Sir Nicholas was someone who did not seek attention for what he did.

He said: “He didn’t look for fame or fortune, it (the kindertransport) was just something he did.”

Sir Nicholas’s actions still provide lessons for today, said Oxfordshire-based grandfather-of-seven John Fieldsend.

The 84-year-old, who lost his parents and a number of other family members to concentration camps, said: “He was an amazing man. I think what we can learn is that one or two people can make a difference.”

He added: “He was not your public idea of a hero, very quiet, very unassuming. Even after the rescue, he really gave his life to charity.”