By Elizabeth Piper and Andrew MacAskill
LONDON (Reuters) -Eurosceptic Conservatives rubbished a key element of a deal with the EU on Northern Ireland as "practically useless" on Tuesday, calling on lawmakers to study a legal review of British Prime Minister Rishi Sunak's plans before deciding how to vote.
Sunak has sought to end years of wrangling in his Conservative Party over Brexit by revisiting and tackling one of the trickiest parts of the years-long negotiations - to ensure smooth trade to Northern Ireland without creating a so-called hard border with Britain or the European Union.
But his solution, the Windsor Framework - a modification to an earlier agreement - has so far been largely rejected by the two groups he most wanted to win over, the European Research Group of eurosceptic Conservatives and the biggest unionist party in the province, the Democratic Unionist Party (DUP).
The one glimmer of hope for a British leader who has sought to end the toxic ties with the EU of his predecessors Boris Johnson and Liz Truss, is that the ERG, long a thorn in the side of several British prime ministers but now a somewhat diminished force, will allow its members to vote as they wish.
The decision to not vote as a bloc could reduce the size of any rebellion and allow Sunak to increasingly sideline the group of Conservatives who have all but put paid to earlier attempts to solve post-Brexit trade problems with Northern Ireland.
Their opposition to the "Stormont brake" and the wider Windsor Framework was clear. They said the brake and other measures in the new deal failed to address the "democratic deficit" by restoring power over some laws to Belfast.
"EU law will still be supreme in Northern Ireland," ERG Chairman Mark Francois told reporters. "The Stormont brake is practically useless and the framework itself has no exit other than through a highly complex legal process."
Francois said the ERG would meet on Wednesday morning to determine whether to vote for the brake later that day, but a source said it would be up to individual members to decide.
DECISIVE BREAKTHROUGH?
Sunak hailed securing the deal last month as a "decisive breakthrough", one which would ease post-Brexit trade between Britain and Northern Ireland, firmly root the province's place in the United Kingdom and give lawmakers there a say in whether they must implement EU law.
But the ERG said beyond not removing the sway of EU law from Northern Ireland, the new deal offered only "limited easings" in trade between Britain and the province, and only allowed London to end the agreement through a "highly complex legal process".
The DUP on Tuesday said it could not vote for the brake, which aims to hand the Northern Ireland assembly the power to prevent new EU laws applying to goods in Northern Ireland.
Earlier this month Johnson said he would struggle to vote in favour of the new deal, also criticising it for allowing the bloc to retain too much influence over the province.
Sunak is in no danger of losing the vote as the opposition Labour Party has said it will back it, but he will want to ensure the measure passes with the votes of his party.
He has already reduced the influence of the ERG by keeping or appointing some of its members, such as interior minister Suella Braverman, in his top team of government ministers.
A spokesperson for Sunak urged lawmakers to back it in Wednesday's vote, adding: "The Stormont brake is important and the most significant part of the framework ... A vote against the brake, in factual terms, would lead to automatic alignment with the EU with no say at all."