The first battle lines have been drawn over the Brexit Repeal Bill as the Government confirmed it would not incorporate the European Charter of Fundamental Rights into British law.
Labour has said it will vote against the major legislation unless it contains a provision to put the charter into UK law but the Bill, published on Thursday, confirms it will be ditched.
It is the first of many fierce battlegrounds on the legislation, formally titled the European Union (Withdrawal) Bill.
Liberal Democrat leader Tim Farron has warned ministers they face "hell" as they try to get the Bill, a central plank of the Government's Brexit strategy, through the Houses of Commons and Lords.
Theresa May and Brexit Secretary David Davis have already called on parties to work together to ensure the crucial Bill's passage through Parliament, widely interpreted as an acknowledgement of the difficulties their minority Government faces.
But it has already put itself on collision course with Labour, which poses a significant threat in parliamentary votes and has made the charter a "red line" for support.
It is understood that ministers believe the rights in the charter are already contained in EU rules which the legislation will convert into domestic law on the day of Brexit.
Britain will also retain its own domestic rights and protections and remain a member of the European Convention on Human Rights, so the Government believes leaving the charter will not have a significant real-life effect.
Ministers are also likely to cite a report by the Women and Equalities Select Committee which says the charter would be "difficult to apply" in a domestic context alone.
But shadow Brexit secretary Sir Keir Starmer has made clear Labour would not support the Bill in its current form.
He demanded concessions in six areas, including incorporating the charter into UK law, ensuring workers' rights in the UK do not fall behind those in the EU, and limiting the scope of so-called "Henry VIII powers", which could allow the Government to alter legislation without full parliamentary scrutiny.
The Bill is designed to transpose EU law into British law so the same rules apply on the day of Brexit as the day before, while giving parliaments and assemblies in Westminster, Edinburgh, Belfast and Cardiff the power to drop or change them in the future.
The Government hopes it will give confidence to businesses, workers and consumers that they will not face unexpected changes on the day of Brexit, while ending the supremacy of EU law in the UK.
There is also likely to be a clash over the Bill's creation of Henry VIII powers, which would allow ministers to change laws and create new regulators or quangos without full parliamentary scrutiny for two years after the Brexit date.
The Government has insisted it will be a limited power to correct minor issues in the law and it is understood that the number of new regulators required is estimated to be in single figures.
But with 800 to 1,000 pieces of secondary legislation, known as statutory instruments, likely to be required under the powers and a two-year window in which to exercise them, there are likely to be objections from MPs and peers.
The Prime Minister has committed to leaving the European Court of Justice but pre-Brexit and relevant case law from its judgments will continue to be followed by British judges in interpreting cases so people get the same outcomes in court either side of the exit date.
The Bill does give the Supreme Court and Scotland's equivalent an escape valve to depart from the case law, but ministers expect judges to only use it sparingly.
The Bill was given its first reading in the Commons, which means its title was read out followed by an order for the Bill to be published.
Labour former minister Chris Bryant jokingly shouted "it's his fault" when Brexit minister Steve Baker rose to present the Bill.
It is understood the Government will seek legislative consent motions from devolved assemblies, potentially handing Scottish, Welsh and Northern Irish administrations a veto over the Bill.
A legislative consent motion is the means by which a devolved body grants permission to the UK Parliament to pass a law on something that is a devolved matter.