Labour peer Alf Dubs said he was “shocked and dismayed” the Government has closed down his scheme to help child refugees.
Lord Dubs said the decision broke the “letter and the spirit” of the agreement by ministers to help at least 3,000 unaccompanied children.
Home Secretary Amber Rudd said last month she was shutting the programme and the UK would take just 350 refugees .
Ms Rudd claimed that it was encouraging trafficking and local authorities did not have ability to house any more children.
But Lord Dubs, who was rescued from the Nazis under the Kindertransport scheme, said the Government could have done more.
He said he was “surprised as well as dismayed” the Government had decided to help only 350 children.
The peer said former Home Office minister James Brokenshire had assured him in person the government would “accept the letter and spirit” of his amendment.
“I took that to mean they wouldn’t arbitrarily close it down so quickly. I was shocked,” he told the International Development committee.
He added: “I don’t understand why they have done it. We are talking about relatively small numbers and we know if take children fewer are trafficked.
“I don’t understand in my heart of heart why they government has decided to close it down when they could easily take a few more.”
Lord Dubs said several councils had come forward to say they could take more unaccompanied children.
“It is my belief the scheme should not be closed. The Government should keep the scheme open. When there are legal paths to safety traffickers don’t get in on the act. We know traffickers do business where there are no legal paths to safety,” he told the MPs.
In a separate intervention former Foreign Secretary David Miliband marked the sixth anniversary of the war in Syria by calling for a new international drive to end the conflict.
Mr Miliband, the head of the International Rescue Committee (IRC) charity, said too many civilians had lost their lives through the “extraordinary abuse of international law” during the bitter struggle.
“The message for the sixth anniversary is that 25million refugees (worldwide) are 25million people, and the great danger is that the statistics dehumanise the refugee population.
“These are doctors and dentists and business people and housewives and househusbands and people who are really trying to keep their lives together in the way that you or I do, but trying to do so in appalling circumstances.
“And I think that the message on the sixth anniversary of the Syria crisis is that 500,000 lives have been lost. That’s not a statistic, that’s 500,000 people whose families have been grotesquely affected by this.
“The sixth anniversary is a day to put the humanity back into the conduct of the war and into the pursuit of peace,” he said.