ITV News Correspondent Paul Brand discusses the problems with the bill
Boris Johnson has said it is "necessary" to row back on aspects of a Brexit agreement - and in the process breach international law - in order to "stop a foreign power from breaking up our country".
The prime minister was briefing around 250 backbench Tory MPs after several expressed concern over his plan to implement the Internal Markets Bill - a piece of domestic legislation that would override parts of the Withdrawal Agreement relating to Northern Ireland.
Northern Ireland Secretary Brandon Lewis admitted the plan would breach international law in a “very specific and limited way”, sparking fury among dozens of MPs.
In a bid to stop his own MPs voting the Bill down, Mr Johnson urged them to "understand his point of view".
He told them clauses in the Internal Market Bill are "necessary to stop a foreign power from breaking up our country" and insisted there are still hopes of a Canada-style trade deal.
An amendment has been tabled to the Bill for when it is introduced to the Commons on Monday and rebels believe around 20-30 MPs will vote against the government.
In an early bid to avoid defeat, Mr Johnson, in a conference call, told MPs: "We must not go back to the miserable, squabbling days of last autumn."
Senior Conservative backbencher Sir Bob Neill, who has tabled the amendment, said he is "surprised" and "very disappointed" by the prime minister's plan.
He told Political Correspondent Paul Brand "there's a lot of unease" about the plan and "a number" of colleagues have expressed support for his amendment.
MEPs have said they will block any trade deal unless the UK backs down on the Internal Markets Bill after the European Union accused the UK of an “extremely serious violation” of international law.
A statement from the leaders in the European Parliament and its UK co-ordination group said "the European Parliament will under no circumstances ratify any agreement between the EU and the UK" if there is any law breach relating to the Withdrawal Agreement.
The UK has so far refused to do so, with Cabinet Office Minister Michael Gove telling a meeting with the EU that the UK government “could not and would not” change the legislation.
If the UK does not change its mind by the end of the month, the EU says it will walk away from the negotiating table and abandon all hopes of a free trade deal.
It has also threatened the UK with legal action if it follows through with its plan.
Will there be a trade deal with the EU?
Britain's chief negotiator David Frost has said he will continue to fight for a deal but has warned “a number of challenging areas” remain before a consensus is reached, adding how some divergence was "significant".
The EU’s chief negotiator Michel Barnier said “significant differences” remain.
“The UK is refusing to include indispensable guarantees of fair competition in our future agreement, while requesting free access to our market,” he said.
Talks will resume next week in Brussels, but after eight rounds of negotiations, little progress has been made.
In a statement on Friday, a senior UK negotiating official said "ultimately progress will be determined by whether we get more realism from them on the key areas of divergence".
Both sides say a deal must be reached by mid-October in order for it to be put in place before the Brexit transition period ends at the end of the year.
Big points of contention include state aid, fisheries and a level playing field.
A UK official said "on fisheries their position is still a long a way from the huge change we need to get an agreement".
With around five weeks to go before the deadline, it is hard to see how both sides will agree a deal on so many unresolved aspects.
Why is the EU angry with the UK?
The UK is planning to implement the Internal Markets Bill, under which ministers would take powers relating to the customs arrangements in Northern Ireland after the current Brexit transition period ends on December 31.
The Bill would override elements of the Northern Ireland protocol which is contained within the Withdrawal Agreement.
The protocol, agreed after much difficult negotiation, was intended to prevent the need for the return of a “hard” border with the Republic while ensuring the integrity of the EU single market.
The government has said the measures in the Bill are simply a “legal safety net” to enable it to protect the Good Friday Agreement and the Northern Ireland peace process.
This drew a dismissive response from the EU which said that “it does the opposite”.
Ireland’s Europe Minister, Thomas Byrne, said: “It is completely wrong to say that this is to protect the Good Friday Agreement - in fact, the opposite is the case."
He added: “What they propose to do is put at serious risk the basis of the peace on the island of Ireland."
Aside from angering much of the EU with his plans, Boris Johnson is facing the prospect of a Commons uprising from many of his own MPs over the plan to breach international law.
A Brexit rebellion?
Despite the UK leaving the EU on January 31 this year, talks of a Brexit rebellion have reemerged.
Boris Johnson was elected to replace Theresa May as prime minister so he could "get Brexit done" and he was lauded for achieving what his predecessor could not.
But now, eight months later, it seems the maverick approach that won him so many admirers could spark an uprising similar to the House of Commons defeats that brought down Mrs May.
Politicians in the Lords and Commons are angry about the PM's plan to breach international law with the Internal Markets Bill, which will be introduced in the Commons on Monday.
A number of Tories have indicated intentions to vote against the Bill, including Brexit supporter Sir Roger Gale, who told ITV News he will reject it, no matter what amendments are made.
But Business Minister Nadhim Zahawi has said Tory MPs could have the whip removed if they vote against the government.
At least 40 Tories would need to rebel against the government in order to force a defeat on the Bill, meaning a loss is unlikely.
Sir Bernard Jenkin, the leader of the strongly pro-Brexit European Research Group, said Mr Johnson “should be more mindful of the reputational damage of playing such hardball”.
Lord Michael Howard has became the third former party leader, after Theresa May and Sir John Major, to criticise the plan.
Speaking in the House of Lords, he accused the ministers of damaging the UK’s “reputation for probity and respect for the rule of the law”.
Senior Conservative backbencher Sir Bob Neill, who chairs the Commons Justice Committee, is tabling an amendment to the Bill which he said would impose a “parliamentary lock” on any changes to the Withdrawal Agreement.
Among its supporters are Theresa May’s former deputy, Damian Green.
Sir Bob told Times Radio: “We are not natural rebels. We’ve all served as ministers, we know that this is a serious job, and we do our best to take the job seriously. So we don’t do anything like this lightly.
“So I hope it’s at least an indication as a Government that really, you need to think very hard and carefully about going down this route. For heaven’s sake, try and find some other way.”
Post-Brexit trade deals outside the EU:
International Trade Secretary Liz Truss announced that the UK had secured a free trade agreement with Japan – Britain’s first such post-Brexit deal.
It is estimated the deal will boost trade with Japan by £15.2 billion.
Ms Truss said: “This is a great deal for Britain, going beyond EU-Japan in key areas like digital & data, financial services and food & drink.
“A British-shaped deal that delivers for the whole country."
Elsewhere, however, a senior US politician has indicated the UK must obey terms of the Withdrawal Agreement if it wants trans-Atlantic trade deal.
Nancy Pelosi, the speaker of the US House of Representatives, warned there will be “absolutely no chance” of a US-UK trade deal passing Congress should the Government override the Withdrawal Agreement.