The Northern Ireland assembly has unexpectedly voted in favour of calling for an extension to the Brexit transition period, arguing that the UK government cannot impose complex border checks down the Irish Sea while Britain is occupied with the coronavirus crisis. In a surprise development, nationalist, green and social democratic parties held sway in Stormont, saying business cannot prepare for a no-deal Brexit in the middle of a pandemic. The motion proposed Matthew O’Toole, the SDLP’s Brexit spokesman, had not been expected to carry after opposition was expressed by the Democratic Unionist and the Ulster Unionist parties. O’Toole, a former Downing Street adviser, said London would have to take the vote seriously as the assembly was “uniquely recognised as a named party in the withdrawal agreement” and Stormont had a substantial role in the implementation of the Ireland and Northern Ireland protocol. He said: “This is not about rerunning the referendum, it’s about accepting that we are in the middle of the most serious public health crisis in living memory. We are also facing a significant economic recession that will put businesses and jobs at risk. This is not the moment to attempt to rupture and renegotiate our largest trading relationship.” O’Toole added that the Stormont vote would “send a powerful message” to Boris Johnson in relation to his implacable opposition to extending the transition period without consent from Northern Ireland. The special protocol on Northern Ireland was agreed in January after a deal struck by the prime minister and his Irish counterpart, Leo Varadkar, to avoid a border on the island of Ireland. It involves checks on trade crossing the Irish Sea which will come into effect as soon as the transition period ends, whether there is a trade deal or not. Under the withdrawal agreement, these checks would hold for at least six years. Businesses have said there is simply not enough time to put IT systems for new customs arrangements, VAT and regulatory checks in place. Both the DUP and the UUP voted against the motion, having argued on Monday that it would be better to postpone such a move until the outcome of this week’s Brexit talks between Brussels and London was known. Green party MLA Rachel Woods said businesses were already facing survival issues with the Bank of England foreseeing “the worst recession in 300 years”. The government “must take account of the shockwaves the Covid-19 crisis has sent throughout our entire society and the fact that Northern Ireland as a whole is not ready or adequately prepared for the protocol [Brexit arrangements] coming into effect in January”, she said. The EU and the UK embarked on the fourth round of talks on Tuesday but few expect any breakthrough with both sides sticking to their rpositions. Johnson has already made it plain that he will not seek an extension to the transition period by the legal 1 July deadline for such a request, raising the possibility of no deal at the end of the year.