Legislation to sever political, financial and legal ties with the European Union is vital to ensuring Britain leaves the bloc in an orderly manner, Brexit minister David Davis has said.
Mr Davis also said the powers offered by the EU withdrawal bill, which seeks largely to copy and paste EU law into British legislation, would allow the government to make sure the statute book works on the day Britain leaves the EU.
"This bill is vital to ensuring that as we leave, we do so in an orderly manner," Mr Davis said at the start of a debate in parliament on the bill.
British MPs have begun two days of debate in the House of Commons on the European Union (withdrawal) bill - known as the repeal bill.
Mr Davis last night issued an appeal to MPs to work with him on what he called the foundation upon which the UK will legislate for years to come.
The EU repeal bill will transpose huge amounts of EU law on to the UK statute books in readiness for Brexit.
Speaking before the start of the debate, Prime Minister Theresa May urged MPs from across the House to work towards the "shared aim" of securing the best possible Brexit for Britain.
But Labour sources insisted the bill was "completely unacceptable", as it hands wide-ranging authority to ministers to amend the law without securing parliamentary consent under so-called Henry VIII powers.
Shadow Brexit Secretary Keir Starmer insisted that Labour's decision to vote against the bill at second reading on Monday was not an attempt to frustrate or delay Brexit, but was designed to stop an undemocratic "power grab" by ministers.
But the decision was condemned as a "mistake" by Leave-backing Labour MP Graham Stringer, who said: "I think it would be an absolute breach of trust between members of Parliament and the electorate if one was to try to block the Brexit bill, which is what this is."
Meanwhile, senior EU figures cast doubt on the prospects of Brexit negotiations moving on to their second phase, covering future trade relations, by October as planned.
The president of the European Council Antonio Tajani told the Politico website that he would ask the European Council to postpone until December its assessment of whether sufficient progress had been made to proceed to phase two.
And former European Council president Herman van Rompuy told the BBC that the chances of making the necessary progress by October were "in the neighbourhood of zero".
But Mr Davis told the House of Commons there was a "very good prospect" of Britain negotiating bespoke transitional arrangements with the EU for a period after the official date of Brexit in March 2019.
He said: "I believe that the benefits of a transitional arrangement are both ways, they're symmetrical, they apply equally to France or Holland or Germany or Denmark, as they do to us."
Staying in the single market during the transition period, as Labour proposes, would be "the worst of all outcomes", said Mr Davis.
The debate will continue on Monday.
