Political stability in Northern Ireland cannot be held hostage over infighting within the Conservative Party, Michelle O’Neill has warned.
There has been an expectation that a British government bill to override aspects of the contentious Northern Ireland Protocol will be published this week.
Critics of Mr Johnson claim the aim of the bill is more about shoring up support for his leadership among the hard line Brexiteer wing of his party, rather than its stated purpose of achieving greater consensus within Northern Ireland for the post-Brexit trading arrangements.
Powersharing at Stormont is on ice after the DUP refused to re-establish a devolved executive following last month’s Assembly election in protest at the protocol, which has created economic barriers on trade between Great Britain and Northern Ireland.
Ms O’Neill tweeted: “Our political stability cannot be a hostage to Tory in-fighting.
“This and DUP boycott of Government is hurting the public at a time when we should have their backs.
“Boris Johnson’s threat to Protocol is to risk their entire agreement with EU on withdrawal & with colossal impact.”
Stormont DUP minister Edwin Poots said a sizeable rebellion against the British prime minister could have an impact on the proposed legislation to unilaterally scrap parts of the protocol.
“Obviously if there’s a large rebellion against the Prime Minister that may have an impact,” he told the PA news agency.
“We’ll wait and see what happens.
“But we’ll deal with whatever circumstances we encounter.
“We’ll deal with whoever will have to deal with, but it’s for the Conservative Party to identify who they want to be their leader.”
Asked if the DUP favoured any other Conservative MP to succeed Mr Johnson if he was to be defeated, Mr Poots said: “We’re not getting into that because we’ll deal with who the current prime minister is.
“Until that prime minister happens to change and then we’ll deal with that person (the successor), but at this moment in time the Prime Minister is Boris Johnson and tonight may change nothing on that front.”
Alliance Party deputy leader Stephen Farry tweeted: “To Conservative MPs, do not use Northern Ireland and future of protocol as pawns in the Confidence Vote in Boris Johnson or any future leadership ballot.”
SDLP leader Colum Eastwood urged Conservative MPs to call time on Mr Johnson’s premiership.
“Boris Johnson’s leadership has been characterised by a cynical corruption of the ideals of public service,” he said.
“He has warped the principles of honesty and integrity in public life through a sustained campaign of dishonesty designed with only his own personal ambition in mind.
“The Sue Gray report was a stark dismantling of the pretence that Boris Johnson cares about anyone else.
“Self-gratification, parties, cake and wine while people were making the most severe sacrifices in the name of community speaks directly to his character and his leadership.
“Tory MPs have the opportunity to call time on the politics of ego, the casual law breaking and the culture of dishonesty which has infected public office during this administration.
“Anything less than a vote of no confidence in this Prime Minister is an endorsement of the corruption of democratic norms.”