Lord Dubs sits in the House of Lords tea-room savouring the taste of victory.

Earlier this month, the 84-year-old former Kindertransport refugee succeeding in getting the government to rethink its policy on accepting child refugees from Europe.

The U-turn came after the peer refused to accept defeat when MPs voted down his amendment to the Immigration Bill currently going through Parliament.

"If I let a bit of opposition dissuade me, I'd have never got anywhere," he says in between sips of tea.

Alf, as he likes to be called - because titles are "nerdy and no good for talking to people" - dunks a biscuit into his cup and expands on why he carried on fighting when the government seemed adamant that it would not commit to allowing more unaccompanied child refugees into the country.

"If at first you don't succeed, try and try again. It is what Nicky Winton taught me and it is what he would have said to me if he were around today."

Born in Prague, Lord Dubs was one of 669 Jewish children saved from the Nazis by the British stockbroker Sir Nicholas Winton, who got the refugees on to trains to the UK.

Almost 80 years on, the Labour peer had proposed an amendment to the Immigration bill calling on the UK to accept 3,000 child refugees. That amendment was rejected by MPs in April, with Conservative members being directed by the government to vote against it.

Undeterred, he sought a compromise with the Home Office, agreeing to drop the figure of 3,000, on the understanding that the government would withdraw its opposition.

"The government was pulling out all stops to vote it down the first time round. But there was a momentum gathering and public opinion was shifting, which helped changed the tide."

At Prime Minister's Question Time on May 4, before the revised amendment came back to the Lords, David Cameron announced to MPs: "It won't be necessary to send the Dubs amendment back, it doesn't mention a number of people. We are going to speak to local authorities to see what we can do."

Lord Dubs says: "It was looking like the government were going to lose second time around. Conservative MPs were all coming out saying they supported it. So Cameron had to cave."

But Dubs, a former director of the Refugee Council is not inclined to gloat. "No one likes to lose, do they?," he adds. "But the government did so quite gracefully."

The peer now hopes that, by September, "several hundred, if not thousands," of unaccompanied child refugees will be "settling down with foster parents and going to school."

He explains: "The government is already speaking to local authorities about how many they can take, and what foster families they have ready. Of course, they will have to vet the foster parents and find out they are fit and proper people.

"But the ideal situation is that existing families with children will take a couple or one extra child and look after them until they're 18 years old."

And while asking a family to take on a child as young as seven until he or she is 18 might sound like a huge commitment, the peer adds: "I've had loads of people contact me to say they want to do it. I've even had Conservative MPs and one peer who has said his family is happy to take a refugee child. I don't think we are short of people who want to help."

Leaving the tea room, Dubs is eager to show off the memorial plaque dedicated to the generosity of British people for welcoming the Kindertransport children that is displayed near the Commons chamber.

"Take a photograph," he urges, at which point the Sergeant of Arms, hovering nearby, intervenes. "Come on Alf, you know you can't do that," he says sternly.

Continuing through the corridors, Lord Dubs is almost bouncing along like a newly elected MP on his first day in Parliament. He talks as he walks, lavishing praise on the Jewish community for its role in getting the government to change its mind.

"They were fantastic. They lobbied hard, they were active and they were keen. And, as a community, our voice carries weight on this issue because of our history," he said. And it is the fact that "the community has got behind an amendment that will help Muslim children" that he finds most inspiring. "I just think it is great," he beamed.

Lord Dubs has spent 30 years in political life, having been ennobled in 1994 after serving as MP for Battersea. At this stage of his career, it must be tempting to opt for the quiet life.

On the contrary, he says: "It is easy to take a back seat and have coffee all day and just meet this person or that. But it is such an opportunity to be here and a privilege. What is the point if you don't do something"

Lord Dubs, who discovered he was saved by Sir Nicholas when his story was broadcast on BBC TV's That's Life in 1988, later met Winton in person and they became great friends, regularly "talking about Labour and politics.

"Some people say I'm only motivated to help refugees by my heart or my personal experience," he says. "But I say no, there's logic to it, a humanitarian need. The case for the amendment doesn't depend upon me having moved it."

Lord Dubs agrees with David Cameron's argument, that the current refugee crisis is not the same as the one he and others faced, when fleeing the Nazis:

"Of course we were fleeing from the gas chambers, and these children are not. But they are young, and they are vulnerable and they are in danger.

"I just came back from Calais, where I met half-a-dozen Afghan children. Some were as young as seven or eight and they were all alone. Their parents had been killed by the Taliban.

"So, for me, it confirmed there are children out there in need of our amendment. I've even got paperwork for the ones I've met and I will do my best to help them."