MPs have been warned by David Davis that voting against the Brexit repeal bill would amount to backing a "chaotic" exit from the European Union.
The Brexit Secretary stressed the British people "did not vote for confusion" in last year's referendum and Parliament should respect that when it divides on the European Union (Withdrawal) Bill for the first time.
Labour will vote against the legislation, arguing so-called "Henry VIII" powers in the Bill that would allow ministers to alter laws without full parliamentary scrutiny amount to a "power-grab".
But Mr Davis's words could weigh heavy on Labour MPs from Leave-backing constituencies, with sources estimating around a dozen could rebel against Jeremy Corbyn's orders.
The Liberal Democrats, who will oppose the legislation, have urged the Labour leader to sack any frontbenchers who defy the whip or risk his party's shift towards a "softer" Brexit being exposed as a "sham".
Several Tory MPs have expressed disquiet over the Bill but are expected to back it after the conclusion of second reading, its first Commons stage, late on Monday or in the early hours of Tuesday.
But they have warned they are ready to back amendments to the Bill at future stages, raising the prospect of the minority Government being bounced into concessions to avoid defeat in House of Commons votes.
Ahead of the debate, Mr Davis said: "A vote against this Bill is a vote for a chaotic exit from the European Union.
"The British people did not vote for confusion and neither should Parliament.
"Providing certainty and stability in the lead up to our withdrawal is a key priority.
"Businesses and individuals need reassurance that there will be no unexpected changes to our laws after exit day and that is exactly what the repeal bill provides.
"Without it, we would be approaching a cliff edge of uncertainty which is not in the interest of anyone.
"That's why I'm urging all MPs of all parts of the UK to come together in support of this crucial legislation so that we can leave the European Union safe in the knowledge that we are ready for day one of exit."
The Bill overturns the 1972 Act which took Britain into the European Economic Community and incorporates relevant EU laws into the UK statute book to prevent black holes in the law at the point of Brexit.
Three votes are expected - on a Labour amendment, the main second reading motion and the programme motion, which sets out the time available for MPs to go through the Bill line-by-line in the Commons.
There are currently a guaranteed 64 hours over eight days for committee stage, when amendments can be made, but concerns have been expressed by Tory and Labour MPs that this will not be enough time given the constitutional significance of the legislation.
If the Government motion setting out the time for debate is defeated ministers will have to consider an alternative timetable.
The votes are likely to take place in the early hours of Tuesday morning.
Labour former minister Caroline Flint said she would defy Mr Corbyn's orders and would not oppose the legislation, arguing that Labour MPs should work to improve rather than kill the Bill.
The Don Valley MP said a defeat for the Bill would cause "huge problems" and told BBC Radio 4's Today programme: "I do believe that in respecting the outcome of the referendum, in respecting what I said to my electors in the general election just a few months ago, it is important that we get on with the job of making sure we can have as smooth an exit from the EU as possible."