London (CNN) The scale of the task facing UK legislators as they try to extricate Britain from the European Union was revealed on Thursday when the British government set out how the process would work.

Unveiling plans to convert EU law into domestic law, the government disclosed that 12,000 EU regulations are in force in Britain. About 7,900 "statutory instruments" -- government orders -- have implemented EU directives. Some 186 acts of Parliament passed between 1980 and 2009 "contained a degree of EU influence," the government said.

As the policy document that paves the way for the so-called Great Repeal Bill was published, Brexit Secretary David Davis said the government was determined to "get the right deal for every single person" in the United Kingdom.

"It will provide certainty and clarity for businesses, workers and consumers across the United Kingdom on the day we leave the EU," Davis said of the bill. "It will mean that as we exit the EU and seek a new deep and special partnership with the European Union, we will be doing so from a position where we have the same standards and rules. But it will also ensure we deliver on our promise to end the supremacy of European Union law in the UK as we exit."

Laws and rules covering areas as diverse as workers' rights, environmental regulations and how the financial services industry operates will need to be converted into UK statutes. While some EU laws will then be repealed, others will be replaced or maintained in a piecemeal fashion.

The publication of the policy document, or white paper, comes a day after the UK government formally served divorce papers on the European Union by triggering Article 50 of the Lisbon Treaty -- beginning a legal process that must end in two years' time with Britain leaving the EU.

Sweeping powers

The UK government said its Great Repeal Bill, first announced in October, would "allow for a smooth and stable transition as the UK leaves the EU, ensuring that, wherever practical, the same rules and laws will apply after exit day."

It will begin by repealing the European Communities Act 1972, which gives EU law supremacy over UK law, and then transpose EU law into domestic law so that no "large holes" are left in the statute book.

UK politicians will then be able to make whatever changes are necessary through the use of secondary legislation, it said. According to the Department for Exiting the EU, these will involve "mechanical changes that ensure laws function properly after EU exit" rather than policy shifts.

But campaign group Global Justice Now warned this week that the Great Repeal Bill has "the potential to grant the government an almost unprecedented level of unaccountable power" if, under so-called Henry VIII clauses, it gives ministers "the power to repeal rights, protections and standards outside of parliamentary scrutiny." The powers are named for a statute passed in 1539 which allowed English monarch Henry VIII to legislate by proclamation.

Davis sought to reassure lawmakers Thursday, saying that the powers granted to ministers to "correct" laws so they still work after Brexit would be "time-limited" and that Parliament would need to be satisfied they were appropriate.

"Given the scale of the changes that will be necessary and the finite amount of time available to make them, there is a balance to be struck between the importance of scrutiny and correcting the statute book in time," he added.

Although EU case law will still be considered for EU rules converted into domestic law, Davis said, the European Court of Justice will no longer have supremacy over the UK Supreme Court.

Devolved administrations in Wales, Scotland and Northern Ireland can expect to see a "significant increase" in their decision making powers in areas such as agriculture where they have control, he said.

A House of Lords select committee report this month said the UK government and Parliament face a "unique challenge" not only in the scale and complexity of the task, "but also by the fact that in many areas the final shape of that law will depend on the outcome of the UK's negotiations with the EU" but it must be ready to come into effect on the day of Brexit.

'Blackmail' row

The Article 50 letter, signed by Prime Minister Theresa May, suggested that a failure to reach a Brexit deal "would mean our cooperation in the fight against crime and terrorism would be weakened." That prompted claims that May was threatening to use the safety of UK and European citizens as a bargaining chip in Brexit talks

Davis played down the suggestion of a rift with the EU earlier Thursday. "This is not a threat. This is a statement of the fact that this would be harmful for both of us, not one of us," he told the BBC. "It's an argument for having a deal. That's the point. That's what we're after," Davis said.

The European Parliament's co-ordinator for Brexit, Guy Verhofstadt, said the EU would oppose any attempt by Britain to link security with an exit deal.

Asked if he thought May was engaged in "blackmail," Verhofstadt told a press conference in Brussels on Wednesday: "I try to be a gentleman, so towards a lady I don't even use or think about the word 'blackmail.'"

The tussle over security overshadowed the British government's attempt to strike a conciliatory tone with the EU. In the Article 50 letter, May said she hoped Britain and the EU would remain the closest of allies and that the UK sought a"deep and special partnership." She also made clear that she wanted to avoid walking away with no deal.

French President Francois Hollande, in a phone call with May on Wednesday, appeared to echo a point made earlier by German Chancellor Angela Merkel that any discussions of the "future relationship" between the UK and EU would have to take place after the divorce.

A number of European leaders spoke Thursday while attending a meeting in Malta of the center-right European People's Party grouping.

European Commission President Jean-Claude Juncker said,"Brexit isn't the end of everything. We must consider it to be a new beginning, something that is stronger, something that is better."

"Brexit has made us, the community of 27, more determined and united than before. And I can say that we will remain more determined and united in the future," said European Council President Donald Tusk.