Peers have backed a move to prevent a hard border between Northern Ireland and the Republic of Ireland.
They voted by 309 to 242, with a majority of 67, in support of an amendment to the EU Withdrawal Bill championed by former Conservative Party chairman Lord Patten.
The amendment requires the UK Government to act in a way compatible with the Good Friday Agreement and to bring in Brexit in a way that does not lead to a hard border between Northern Ireland and the Republic of Ireland.
It is the tenth defeat for the Government on the EU Withdrawal Bill in the upper house.
Responding to the Government defeat, Labour’s shadow Brexit minister Jenny Chapman said: “This vote sends a clear signal to the Government that they must urgently find a solution to the Northern Ireland border.
“Ill-conceived compromises and unrealistic technological solutions are simply not good enough. The Government’s failure to act is holding back the Brexit negotiations and creating deep uncertainty for communities in Northern Ireland.
“Ministers should back this amendment and accept Labour’s call for a new comprehensive customs union with the EU.”