LONDON (Reuters) -- Prime Minister Theresa May’s Brexit deal came under fire from allies and opponents alike Wednesday after the government was forced to publish legal advice showing the United Kingdom could be locked indefinitely in the European Union's orbit.
After a string of humiliating parliamentary defeats for May the day before cast new doubt over her ability to get a deal approved, U.S. investment bank J.P. Morgan said the chances of Britain calling off Brexit altogether had increased.
As investors and allies tried to work out the ultimate destination for the world's fifth largest economy, the Northern Irish party which props up May's government said legal advice about the deal was "devastating".
May was forced by Parliament to publish advice from the government's top lawyer about the fallback mechanism, or backstop, to prevent the return of border controls between British-ruled Northern Ireland and the EU-member Irish Republic.
"Despite statements in the Protocol that it is not intended to be permanent and the clear intention of the parties that it should be replaced by alternative, permanent arrangements, in international law the Protocol would endure indefinitely until a superseding agreement took its place," the advice said.
"In the absence of a right of termination, there is a legal risk that the United Kingdom might become subject to protracted and repeating rounds of negotiations."
Brexit, the United Kingdom's biggest economic and political shift since World War Two, has repeatedly plunged British politics into crisis since the shock 2016 vote to leave the EU.
Now May is trying to get her deal approved by a Parliament which shows every sign of striking it down in a vote on Dec. 11. It is unclear what happens if the deal is rejected as Britain is due to leave on March 29.
Nigel Dodds, the deputy leader of the Northern Irish Democratic Unionist Party, said the legal advice proved that Northern Ireland would be treated differently to the rest of the United Kingdom.
On Tuesday, just hours before the start of a five-day debate in the British Parliament on May's Brexit deal, a top law official at the European Court of Justice said Britain could pull back its formal divorce notice.
"The UK now appears to have the option of revoking unilaterally and taking a period of time of its own choosing to decide what happens next," J.P. Morgan economist Malcolm Barr wrote in a note to clients.