When designing a weapon, it is a good idea to imagine it falling into the wrong hands. The same principle applies when politicians ask for new powers: benefits of the advertised use must be weighed against the potential for misuse. There are legislative weapons so powerful that no government can be trusted with them.

The Brexit bill is cataclysmic. Only a swerve will save us | Polly Toynbee Read more

The EU withdrawal bill’s advertised use is the disentanglement of British and European laws. The threads are densely woven. Time is short. The tempo is set by the article 50 withdrawal process, according to which EU membership expires on 29 March 2019. On that day, heaps of laws will cease to function unless they have been naturalised as British statute. The bill does that at a stroke. It then gives ministers a set of tools to tweak and purge any law – not just those of EU provenance – judged to contain “deficiencies” that need “correcting”.

These are “Henry VIII powers”, thus named after the Tudor monarch’s disdain for parliamentary restraint. It isn’t a compliment. The bill assembles an edifice of regulations amounting to the biggest peacetime transfer of power from the legislature to the executive in living memory. There are a handful of limitations: on making new criminal offences and raising taxes, for example. But as far as most statute is concerned, it is open season – a blank canvas for ministers to daub the post-Brexit landscape in colours to match their ideological taste. They can paint over rules governing anything from the quality of the food we eat and the air we breathe to the rights we have at work.

Set aside the question of whether it is wise to be quitting the EU. It is happening. There was a referendum. Parliament voted to trigger article 50. The task addressed by the withdrawal bill is unavoidable. Some kind of short cut is justified – otherwise parliament would be clogged up with bills rewriting EU law for decades. But MPs are not being offered some bespoke mechanism, with checks and balances, to make a heavy-duty job more efficient. They are presented with a monster, stitched together from arcane procedures traditionally used to adjust small-fry rules. They are invited to surrender to this beast any say in what Brexit means for their constituents.

One way to achieve the same goal would be a bill suspending parliament altogether and replacing it with a Supreme Revolutionary Council issuing Brexit decrees, styled as direct expressions of the will of the people.

The government rejects that characterisation on technical grounds. There are “sunset clauses” that mean most of the Henry VIII powers expire two years after “exit day”. And statutory instruments can be voted down. The second point is the weakest. There is not space here to explore the procedural labyrinth in which a tenacious MP might hunt down and extinguish a bad regulation. It calls to mind Arthur Dent, in the opening chapter of The Hitchhiker’s Guide to the Galaxy, learning that his house is to be demolished from a council notice that was displayed in a cellar with no lights, accessible by no stairs, in a locked filing cabinet, in a disused lavatory, behind a door with a sign saying Beware of the Leopard.

The withdrawal bill will generate thousands of little demolitions. Many will be churned out in the months running up to the article 50 deadline, when neither the ministers signing them nor the MPs who are meant to scrutinise them will have the capacity to do the job well. Officials will make law straight from Whitehall, guessing at the wishes of their bosses or following whims of their own. Clause 7 (5) of the bill creates a power to replace EU agencies with new bodies (yet to be imagined) that will, in turn, have powers to make law – thus kicking the process out of the Palace of Westminster altogether.

The sunset clauses are a sham. The bill names no “exit day” and has no procedure for setting one, beyond the word of a minister. Multiple dates can apply in different circumstances. Regulations could be made within the time limit, setting up powers to endure after the legal sun has set. Suppose the Brexit deal contains a five-year transitional phase. A minister decrees that, for certain purposes, “exit day” is not in March 2019, but 2024. The Henry VIII clauses would run until 2026. Even without that extension, two years is ample time for stupid things to be done in the name of legal “correction”.

The white paper that prefigured this bill said its powers would be applied only where “necessary” to make law Brexit-ready. This has now become a ministerial judgment of what is “appropriate”. The change is important and not accidental. Necessity is a threshold of legal protection, meaning government use of the powers could be challenged in court. The appropriateness test is much weaker. It is a licence to rewrite the statute book in pursuit of partisan political agendas.

The Guardian view on EU withdrawal bill: a cynical power-grab | Editorial Read more

If Conservative MPs are relaxed about this, they might want to imagine how they would treat the same bill if drafted by Jeremy Corbyn and John McDonnell. They would denounce it as a shameless power-grab, a sinister device to hijack Brexit for revolutionary, Venezuelan-style socialism. I have no idea what Labour would actually do with this law in the wholly feasible scenario in which they inherit its powers. No one knows what the Tories intend to do with it either. Theresa May pleads for the benefit of the doubt, even when her last such request – the electoral bid for a personalised Brexit mandate – cost her a Commons majority.

The prime minister asks for trust. She wants us to let her apply a general anaesthetic to parliament so she can whisk the body of British law into an operating theatre, out of sight, where she, David Davis, Liam Fox, Boris Johnson and the rest will carve, stitch, bypass and amputate whatever they deem “appropriate”.

Some Brexit enthusiasts itch to get us under that knife. They depict any hesitation as remainer sabotage. The government will rely on residual pressure from the referendum result to drive their bill forwards, plus a streak of complacency around the resilience of democratic norms. There is a collective glazing over of eyes that meets arguments of constitutional principle and theoretical worst-case scenarios. Britain does not generally imagine itself vulnerable to tyranny. But no one doubts our susceptibility to bad government. And the sight of Donald Trump in the White House is a reminder that unwritten conventions offer no protection against abuses of office. Vast, unchecked powers should not be granted on the basis of blind faith that ministers will use them modestly.

There are no safeguards in the withdrawal bill. We get only the impatient muttering of bogus doctors as the trolley rolls into surgery: “Nothing to worry about, breathe in the gas, go to sleep, you won’t feel a thing ...” Leavers would not take that from remainers. Tories would not take it from Labour. And no MP who cares about parliamentary scrutiny of Brexit, or anything else, should take it from Theresa May.

• Rafael Behr is a Guardian columnist