Editor's Note: (Robin Oakley is a former political editor for the BBC and The Times. He was CNN's European Political Editor between 2000 and 2008. )
London(CNN) Theresa May is taking a lead from a frequently divorced former monarch in preparing the way for life after the Brexit break-up.
In order to deal with tens of thousands of EU laws, regulations, treaties and directives that must be incorporated into UK law on Brexit Day, the British government wants to invoke controversial powers that date back 500 years to the time of King Henry VIII.
The so-called "Henry VIII clauses" in the Great Repeal Bill, plans for which were published on Thursday, will give ministers and civil servants sweeping authority to comb through the vast EU legislative soup and decide which bits to keep, which to amend, and which to repeal in their entirety. Crucially, ministers can wave the decisions through without recourse to the House of Commons.
The government argues the powers are needed in order to get the job done in a limited time and avoid legal chaos on the day Britain leaves the EU. But opposition politicians fear a power grab.
These arcane British parliamentary procedures date back to the 16th century. In 1539, King Henry VIII, not a man it was easy to cross, published a Statute of Proclamations, which gave his decisions and commands the same legal status as legislative acts passed by Parliament. Since then, governments have on rare occasions used Henry VIII clauses to repeal or amend legislation by a "secondary act" which involves little or no Parliamentary scrutiny.
Their use in the Great Repeal Bill is being presented as a common-sense way of avoiding wasting Parliamentary time over tedious, technical regulations on consumer labeling or food packaging. Additionally the government may not know which bits of EU law are affected until the shape of the Brexit deal emerges, which could be perilously close to "Brexit Day" on March 29 2019.
But a briefing paper on the Great Repeal Bill produced by the House of Commons Library, which provides non-partisan research and analysis for MPs and parliamentary staff, said the "scale of the technical changes needed could mean that the powers included are nonetheless relatively significant."
Keir Starmer, Brexit spokesman for the opposition Labour Party, said that given the "sweeping" nature of the powers in the white paper, "rigorous safeguards" could be expected. But "none are to be found," he told MPs when the government presented the white paper on the Great Repeal Bill on Thursday.
David Davis, Secretary of State for Exiting the European Union, attempted to reassure MPs, saying the powers would require the approval of MPs and would be "time-limited".
The Government has already been taken court in efforts to give Parliament more say in the Article 50 process. Parliamentarians remain suspicious of anything that might eat into their right to scrutinise and alter legislation.
The House of Commons Library report notes: "Concerns over the constitutionality of Henry VIII powers have been growing in recent years, and their use in this legislation -- which has the ostensible purpose of empowering Parliament, and which represents a major constitutional change -- is likely to provoke extensive debate."