Brexit's Internal Market Bill explained: what is it, and why is it so controversial?

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What's the story?

Aroused from their slumbers with hackles up, the backbench pack were prepared to show some teeth.

It was the chairman of the 1922 committee who seemed to sum up the mood.

“If you keep whacking a dog, don't be surprised when it bites you back,” Sir Charles Walker warned before joining 29 of his colleagues to abstain on the Government’s new Brexit legislation.

Boris Johnson might have gone on to comfortably win his first Commons battle over the Internal Market Bill, but rebels believe many MPs have simply decided to “hold their fire”.

An amendment from Tory backbencher Sir Bob Neill – set to be debated on Tuesday – could yet be the Government’s undoing.

Veteran backbencher Sir Roger Gale, one of two Conservative MPs who voted against the Government on Tuesday night, predicted more of his colleagues could rebel next week.

He said: “I took a view that you fight this tooth and nail at every step. Others have quite clearly decided they want to hold their fire for Bob Neill’s amendment. There is much to play for yet.”

Why is the Internal Market Bill controversial?

The controversial Bill has stoked up division inside the Conservative Party that is reminiscent of the high-stakes Brexit brinkmanship we witnessed last year.

But this time it goes further than Leave or Remain. Prominent Eurosceptics, such as Lord Howard and former attorney general Geoffrey Cox, have raised their concerns over the Government’s admission that the Bill, if enacted, would break international law.

That it would be, as Northern Ireland Secretary Brendan Lewis insisted, in a “very specific and limited way” did little to alleviate their fears.

To date, all living former Prime Ministers, five ex-Conservative party leaders and 30 of the party’s MPs have expressed their discomfort.

Ministers (well, most of them) are standing firm. In the Commons on Monday night, Mr Johnson insisted the legislation was necessary to prevent the EU taking an "extreme and unreasonable" interpretation of the provisions in the Withdrawal Agreement relating to Northern Ireland.

The Prime Minister warned that some in Brussels were now threatening to block UK agri-food exports to the EU, and to insist on tariffs on all goods moving to Northern Ireland from the rest of the UK.

"Absurd and self-defeating as that action would be even as we debate this matter, the EU still have not taken this revolver off the table," he said.

However, shadow business secretary Ed Miliband repeatedly asked the Prime Minister to explain how the Bill would protect Northern Ireland from the threat of a potential food blockade.

“I know you’re a details man. Show me the blockade. I will give way to you,” Mr Miliband scoffed, but the Prime Minister merely shook his head in disdain.

Looking back

The UK’s internal market dates back to the early 1700s, when it was created to ensure “open and unhindered trade” across the four nations.

But when the UK joined the then-European Economic Community in 1973, most of the British trade laws were replaced by European laws.

It was Margaret Thatcher’s government in the 1980s that helped to forge the formal creation of the single market between EU nations.

It was designed to open European markets to British exporters and to level the playing field for UK firms across the continent.

Regarding all EU member states as one territory, the bloc devised rules about everything from food standards to fisheries to ensure consistency across the bloc.

The Internal Market Bill is its proposed replacement, aiming to ensure all four of the UK's home nations are not limited by regulations determined by each devolved Government.

It also aims to guarantee the international community has access to the UK as a whole, knowing the standards and rules are the same throughout.

One of the major issues is how this can apply to Northern Ireland when it shares a border with the Republic of Ireland, which will remain in the EU.

This where the controversy kicks in. The Bill could contradict the Withdrawal Agreement, and therefore international law, as it says ministers could have the power to "disapply" previously agreed rules relating to the movement of goods.

This includes those under the Northern Ireland Protocol.

Anything else I need to know?

On Tuesday Sir Bob’s amendment will be in front of the House and its supporters claim “the momentum is with us”.

The proposal would impose a "parliamentary lock" on any changes to the Withdrawal Agreement, giving Parliament the final say on whether it is appropriate to renege on the treaty.

Rebel MPs believe that up to 20 of their colleagues who backed the Bill this week may be minded to also support the amendment, leaving the Government facing an almost tangible defeat.

However, we might be spared the Commons fireworks of 2019’s Brexit battles.

It is understood that ministers are working to find a “compromise” with the group, with Mr Johnson meeting Sir Bob and some of his supporters before Monday’s Commons vote. Tory rebels say they engaged in “constructive” talks with the Prime Minister, with many MPs increasingly hopeful that a deal can be reached.

One of the group said: “It’s early days but it feels as if we are edging towards a compromise being reached.”

However, the Government may require “small tweaks” to the amendment as it stands to reach an agreement.

The Refresher take

Originally Downing Street threatened to withdraw the whip from rebels who defied the Government, but privately talks have taken a carrot rather than a stick approach.

Boris Johnson has told rebels there is not a “cigarette paper” between them and implied there would be reassurances.

There are suggestions that concessions may also be in the Government’s favour. If MPs vote to trigger the mechanism then it would be more difficult to challenge in court.

So with a few treats, and perhaps a bit of a tummy rub, the rebellion's bark may be worse than its bite.