The British government published plans Thursday for a herculean legislative task: converting thousands of E.U. laws onto the British books as the country begins its Brexit decoupling from Brussels.

The law-changing blueprint landed a day after British Prime Minister Theresa May triggered Article 50, officially serving the European Union divorce papers and beginning exit negotiations expected to last two years.

The swift release of the government’s plans for the “Great Repeal Bill” reflects just how split Britain remains as divorce talks loom with the European Union. British leaders now sense a greater urgency to calm Brexit opponents, including many businesses worried about Britain’s new legal structure.

The repeal bill will see thousands of E.U. laws — covering such topics as workers’ rights, environmental rules and finance regulations — transposed into British codes to provide legal certainty and a “smooth and orderly” departure from the European Union.

The bill seeks to show workers, consumers and businesses that the “rules have not changed overnight,” David Davis, the Brexit secretary, told the House of Commons.

He also said it signaled the end of the supremacy of E.U. law in Britain.

“Our laws will then be made in London, Edinburgh, Cardiff and Belfast,” he said, referring to the capitals of the four members of the United Kingdom.

The plans, published in a policy paper, have been described as a gigantic “cut and paste” job, repatriating 40 years of powers from Brussels to London. From there, Britain will decide which laws to keep and which to scrap — with the government granted new authority to make the changes.

But officials insist that the powers — dubbed “Henry VIII powers” by critics after the imperious monarch — are needed to make “corrections” to E.U. laws once they are taken onto the books.

Some opposition lawmakers called it a “government power grab” and said that the plans give the government too much authority to change laws without parliamentary oversight.

Keir Starmer, the opposition Labour Party’s Brexit spokesman, said that the plans give “sweeping powers” to the executive and that “rigorous safeguards” are needed.

Some Brexit proponents see this as a golden opportunity to scrap E.U. regulations that they consider an infringement on businesses.

The Daily Telegraph, a right-leaning British newspaper, urged the Conservative Party to “promise a bonfire of E.U. red tape in its 2020 manifesto to put Britain on a radically different course.”

Boris Johnson, the foreign secretary, told the Commons earlier this week that Brexit “will be an opportunity for this country to get rid of some of the burdensome regulation that has accreted over the last 44 years” — when Britain joined the group that would evolve into the European Union.

Others say that the regulations are essential and that Britain would suffer if its laws did not closely mesh with the 27 remaining E.U. states.

Caroline Lucas, the co-leader of the Green Party, tweeted that the bill “could undermine 40 years of environmental and social protections with no Parliamentary scrutiny.”

The consequences of the Great Repeal Bill could be widespread, and analysts said that companies across industries will be following events closely.

Mujtaba Rahman, an analyst with the Eurasia Group, said in a briefing note that “an enormous lobbying operation will swing into action as different sectors try to defend their interests during the filtering process.”

“Business will be watching the debate closely,” he said.