Boris Johnson's government last week introduced a bill to override the EU treaty and unilaterally regulate UK trade

London (AFP) - Prime Minister Boris Johnson was set to face down critics on Monday to argue in favour of a new law that his government openly admits will break its EU divorce treaty, as wrangling over Brexit returns to the British parliament.

Furious officials in Brussels have demanded the proposed legislation is withdrawn before the end of the month, and Johnson is facing threats of rebellion and resignations.

But his spokesman said the prime minister would open the debate in parliament later on Monday arguing it was a “critical piece of legislation for the United Kingdom”.

“It’s critical that we get this legislation passed and on the statute books by the end of this year,” he told reporters.

Britain unveiled the proposals last week, conceding it would override the binding Brexit treaty the UK struck with the EU last year in several key areas related to Northern Ireland.

It would see London unilaterally regulate UK trade and state aid within the British province, ignoring the EU treaty which gives Brussels a continuing say over Northern Ireland’s trading relationship.

If the law passes in the coming weeks, Brussels has warned it could scupper ongoing trade deal talks and threatened court action, leaving the prospects of an orderly Brexit in tatters.

- ‘Misgivings’ -

The row revives the bitter wrangling over how to implement British voters’ shock decision in 2016 to quit the bloc, which led to parliamentary deadlock and repeated postponements.

Johnson put a temporary halt to the uncertainty by sealing a divorce deal with Brussels late last year, which he used to win a thumping 80-seat victory in a December general election.

Britain then formally left the EU in January but remains bound by its rules under a transition period until the end of this year as it tries to negotiate a free trade deal with the bloc.

Those talks are currently deadlocked and could be threatened by the bill.

Its intent to wilfully ignore an international treaty and potentially endanger Northern Ireland’s fragile peace has prompted scorn from across the political spectrum, including among some pro-Brexit lawmakers.

All of Britain’s living former prime ministers – John Major, Tony Blair, Gordon Brown, David Cameron and Theresa May – said the country’s international reputation would be damaged if it is seen to break an international treaty.

Geoffrey Cox, who was Johnson’s attorney general during the unlawful suspension of parliament last year, said any breach would be “unconscionable”.

“I think it is wrong that the British government or our parliament should renege on an agreement on which we gave our solemn word,” he told Times Radio.

Meanwhile, Tory MP Rehman Chishti, a former lawyer, quit as Johnson’s special envoy on freedom of religion or belief over the bill.

“Respecting rule of law (and) honouring one’s word are dear to me,” he said in his resignation letter.

- Blind-sided -

Britain claims it needs the new law as an insurance policy in case no trade agreement is struck, and has accused the EU of plotting to break up the UK with a food “blockade” down the Irish Sea, prompting strenuous denials from Brussels.

MPs get their first chance to debate the legislation from late-afternoon Monday, before voting at around 2100 GMT to continue its passage through parliament.

However, more meaningful votes on attempts to change the draft law will come next week.

The government is determined to ram the UK Internal Market Bill through as quickly as possible, and senior minister Michael Gove believes it can avert a full-scale rebellion

Commons Justice Committee chairman Bob Neill has filed an amendment to dictate that parliament, not the government, will have the final say on any changes to the EU Withdrawal Agreement.

It remains to be seen whether Tory rebels can muster the numbers to seriously embarrass the government on Monday or if they hold their fire until future votes.

The main opposition Labour party, which opposed Brexit, says it is open to negotiation about the bill but would rather be talking about coronavirus.

Leader Keir Starmer will not get the chance to respond to Johnson directly after he was forced to self-isolate because a family member had shown symptoms of the virus.