The British government will offer parliament a take it or leave vote on any final EU departure agreement, Brexit Secretary David Davis has announced.
Mr Davis's move was seen as an attempted concession to Conservative rebels who may defy the government this week by voting against separate Brexit legislation transferring existing EU laws to Britain.
However, the bid to head off opposition from restive politicians was met with criticism as MPs claimed the vote would be meaningless and give them little time to consider any eventual Brexit deal.
Mr Davis confirmed that if parliament voted down the withdrawal bill, Britain would leave the European Union with no Brexit deal at all.
He said there would be no withdrawal agreement bill, or vote, if London cannot strike a deal with Brussels.
"If we don't have a withdrawal agreement we can't have a withdrawal agreement bill, full stop."
Details of the bill are tied to ongoing and future negotiations, which will not be revealed until the talks are near completion.
"Once we have reached an agreement we will bring forward a specific piece of primary legislation to implement the agreement," Mr Davis told MPs.
Prime Minister Theresa May's governing Conservatives rely on support from the DUP for a narrow majority in parliament. But the proposal triggered an immediate backlash from rebels within Mrs May's own party.
Conservative MP Heidi Allen said the move was "pointless" and offered "no safeguard if no deal is reached".
Fellow Conservative backbencher Antoinette Sandbach said it was "meaningless" if the timetable slipped beyond the March 2019 EU exit date.
Labour MP Chuka Umunna, co-chair of the cross-party parliamentary group on EU relations, said the move was "totally insufficient" and gave "no guarantee of a meaningful vote".
He said the bill must be amended "to provide for a proper, not a fake, meaningful vote before any exit day".
Chris Leslie, also from the main Labour opposition, called it a "sham offer" that was "totally worthless".
"This is a post hoc, after-the-horse-has-bolted piece of legislation," he said.
"Parliament could do nothing at all to shape the nature of that withdrawal agreement."
The Brexit ministry said the bill was expected to cover issues such as the rights of EU citizens in Britain and British nationals in the EU, divorce payments and an agreement on any post-Brexit transition period.
Keir Starmer, Labour's Brexit spokesman, said the proposed law was "a significant climbdown from a weak government on the verge of defeat" in a series of upcoming Brexit debates.
"For months, Labour has been calling on ministers to guarantee parliament a final say on the withdrawal agreement... They have finally backed down," he said.
Urgent progress required in Brexit talks, British PM told
Meanwhile, European business leaders have told British Prime Minister Theresa May that progress is urgently needed in Brexit talks or British jobs and investment could be lost.
Mrs May hosted senior industry figures from across the continent in Downing Street to hear their concerns and groups represented included Ibec, the BDI and BDA from Germany, Medef from France and the EU-wide Business Europe.
As we leave the EU, we must do all we can to ensure that UK and EU businesses continue to thrive side-by-side. That’s why it was so important to speak to European business leaders in Downing Street this morning: pic.twitter.com/TtQTPgFLc0— Theresa May (@theresa_may) November 13, 2017
Business Europe president Emma Marcegaglia said it was crucial for progress to be made within two weeks in order for trade talks to be given the green light by EU leaders at a summit next month.
Ibec Director General Danny McCoy said that Ireland needed more certainty from Britain about Brexit.
He said that Mrs May was keen to stress that the east/west dimension was as important to Britain as the north/south relationship between Ireland and Britain and this was very important to the business community.
Mr McCoy said the meeting with Mrs May was very positive overall and that Mr Davis was clear that Britain wants a free trade agreement that involves no tariffs or regulatory barriers.
Speaking on RTÉ's News at One, Mr McCoy said: "Prime Minister May was really making the point that the east/west dimension is as important to Britain as the north/south, in the relationship between Ireland and Britain, which I think is really important to the business community.
"But they also stressed that in order for the transition period to be effective, they'll need to know what the final outcome is, so they're really putting pressure to move to the second phase.
"But I think our Government is right: that we do, as a country, need more certainty from Britain before we can deem sufficient progress. So overall very positive."
An EU leaders' summit will take place next month and the European Union's chief negotiator Michel Barnier has previously said the moment was approaching for a "real clarification" of Britain's position on issues such as citizens' rights, the Irish border and the UK's financial settlement.
If the 27 remaining EU members agree next month that sufficient progress has been made on these issues, they will give a green light for negotiations to move on to the questions of trade and transition to a new post-Brexit negotiation.