The Commons has rejected an attempt by Labour to reinstate child refugee protection rights in the Brexit bill.
MPs voted 348 to 252 against the amendment, which would have guaranteed the right of unaccompanied child refugees to be reunited with family living in the UK after Brexit.
The pledge was included in a previous version of the Brexit bill, but was removed after the Tories' election win.
The government said it had "a proud record of helping vulnerable children."
MPs voted on the Labour amendment during a second day of scrutiny of the Brexit bill - or EU Withdrawal Agreement Bill as it is officially known.
That's the legislation implementing Boris Johnson's Brexit deal and it must be passed by both the Commons and Lords if the UK is to leave the EU on 31 January - the current deadline.
Labour's Lord Dubs - who came to the UK as a child to escape the Nazis - had campaigned for the commitment to be included in the bill.
It was included in Theresa May's Brexit bill, but was removed in Boris Johnson's version, something he called "appalling and deeply distressing".
The newly-worded bill replaced the commitment to negotiate with the EU a continuation of the rights of child refugees with a reduced obligation to make statements to Parliament on the government's child refugee policy after Brexit.
What did Labour ask for?
In the Commons, shadow Brexit minister Thangam Debbonaire made the case for the Labour amendment, arguing that removing it from the bill was an "astonishing breach of faith with some of the most vulnerable children in the world".
Backing its return was "about who we want to be as a country".
"It is deeply wrong for the government to seek to remove this provision... just because they can," she went on.
"Family reunion should not need explaining, but it appears it does. Families belong together."
Lord Dubs and shadow Brexit secretary Sir Keir Starmer earlier wrote to Conservative MPs urging them to support Labour's amendment to reinstate the pledge.
They said: "We know that there are many Conservative MPs, including some sat around the cabinet table, who know that this decision was wrong.
"Boris Johnson may have won a majority in Parliament, but he did not win the moral argument to absolve himself of responsibility to some of the most vulnerable people in the world.
"With the numbers in Parliament being what they are, it's up to you - Conservative MPs - to take a moral stance and force the government to rethink its approach on this vital issue."
The Liberal Democrats have also called for the government to rethink what they call an "inhumane" position.
How did the government respond?
Northern Ireland minister Robin Walker told MPs the government was "fully committed" to the principle of family reunion and its policy "has not changed".
However, they will not be backing the amendment to see it guaranteed in law.
Mr Walker said the policy of reuniting families would continue during the transition period while a deal is being negotiated with the EU on the future trading relationship with the UK.
He said Home Secretary Priti Patel had written to the European Commission in October to start negotiations on what would happen after that period's end in December 2020.
"We give very strong support for the principle of family reunion," Mr Walker added.
"But the right place to do that is not in this legislation and we do not need further reporting requirements or legally binding negotiating objectives, as these amendments set out."
What is happening with Brexit this week?
MPs gave their initial approval for Boris Johnson's Brexit bill in December, but it is now undergoing more detailed Commons scrutiny.
The bill covers "divorce" payments to the EU, citizens' rights, customs arrangements for Northern Ireland and the proposed 11-month transition period lasting from 1 February to 31 December.
The bill is expected to comfortably pass its remaining stages in the Commons by Thursday before moving to the Lords.
Brexit Secretary Steve Barclay said the bill would deliver on the "overwhelming mandate" his party had been given by the voters to take the UK out of the EU on 31 January.
While shadow Brexit minister Paul Blomfield said Labour accepted their opponents' decisive election victory had changed the political landscape he said he still believed this was a "bad deal" for the UK and urged the government to proceed "with caution".