Theresa May claims Brexit bill defeat will 'undermine' UK's negotiations with Brussels
Theresa May has warned Tory MPs that any Commons defeats inflicted on the Government's flagship Brexit bill will "undermine" her attempts to get a good deal from Brussels.
In another plea for Conservative unity, the Prime Minister told her backbenchers to think of "the message Parliament will send to the European Union" when they vote on the legislation on Tuesday and Wednesday.
Peers inflicted 15 defeats on the EU Withdrawal Bill, but the Government will seek to either overturn or amend 14 of them.
It emerged tonight that Mrs May is planning a fresh concession to Tory rebels planning to vote against the Government on calls for ministers to negotiate a new customs union with the EU after Brexit.
The Prime Minister is set to table a new amendment which would pledge the Government to explore a "customs arrangement" with Brussels, potentially heading off a rebellion in Wednesday's crunch vote.
Addressing a meeting of the 1922 Committee of Tory backbenchers, Mrs May said: "We must think about the message Parliament will send to the European Union this week.
"I am trying to negotiate the best deal for Britain. I am confident I can get a deal that allows us to strike our own trade deals while having a border with the EU which is as frictionless as possible.
"But if the Lords amendments are allowed to stand, that negotiating position will be undermined."
She added: "The message we send to the country through our votes this week is important.
"We must be clear that we are united as a party in our determination to deliver on the decision made by the British people."
At the same time as the Prime Minister was addressing her MPs, Shadow Brexit Secretary Keir Starmer was facing his critics at the weekly meeting of the Parliamentary Labour Party.
Labour leader Jeremy Corbyn is facing a big rebellion over his decision tell his MPs not to support an amendment calling for Britain to join the European Economic Area after it leaves the EU.