The European Union’s threat to impose a vaccine border between Northern Ireland and the Republic risks reigniting one of Brexit’s bitterest disputes, as senior Tories said the move proved the need for an immediate overhaul of the bloc’s treatment of Northern Ireland. The renewed demands emerged with the EU facing an extraordinary backlash over its bungled announcement of potential export controls on vaccines produced within the bloc. The World Health Organization (WHO) condemned the move and the pharmaceutical industry warned that the measures would damage their vaccination efforts. However, the EU’s initial threat to stop vaccines crossing freely from the EU to Northern Ireland – swiftly withdrawn after it set off a diplomatic crisis between Ireland, the EU and the UK – has also reopened the toxic political row over Northern Ireland’s post-Brexit status. Tory Brexiters were planning this weekend to use the row to demand an overhaul of the Brexit deal over Northern Ireland that has seen trade issues emerge with Great Britain. The row has heaped huge pressure on European commission president Ursula von der Leyen, who has already faced blame over the relative slowness of the EU’s vaccination programme compared with nations such as the US, UK and Israel. The EU’s threat of border controls within Ireland had been part of the bloc’s export control measures on vaccines, designed to tackle delivery shortfalls. In an intervention in the Observer that reveals the alarm the EU’s threat has caused among vaccine makers, the heads of the UK- and Europe-wide industry bodies jointly warn that export bans would leave them “trying to fight the pandemic with our hands tied behind our backs”. “Alongside the scaling up of capacity, companies without Covid-19 vaccines are lending their own manufacturing capacity and expertise to produce even more doses,” write Richard Torbett, head of the UK’s Association of the British Pharmaceutical Industry, and Nathalie Moll, head of the European Federation of Pharmaceutical Industries and Associations. “Export bans undermine this collaborative effort. Companies are working as fast as they can to protect everyone. Export restrictions do no one any good and we urge governments to avoid them.” The WHO has also criticised the EU’s announcement of export controls. Its director-general, Dr Tedros Adhanom Ghebreyesus, said “vaccine nationalism” would only serve to draw out the Covid crisis. Dr Mariângela Simão, WHO assistant director-general for access to medicines and health products, said it was a “very worrying trend”. The Brexit protocol affecting Northern Ireland was designed to stop the need for a border within Ireland. Article 16 of the protocol can be used to override the agreement in certain circumstances. The EU signalled on Friday that it would trigger the clause to stop Northern Ireland becoming a back door for vaccines to enter the UK from the bloc, but ditched the decision after a diplomatic outcry from Dublin and London. However, the row escalated on Saturday after Northern Ireland’s first minister and Democratic Unionist party leader, Arlene Foster, called for the entire deal affecting the region to be redrawn. She said the protocol was proving to be “unworkable” and that serious problems had emerged with trade between Northern Ireland and Great Britain. It is understood that senior Tories will seek to meet the Cabinet Office minister, Michael Gove, to relay their concerns. Theresa Villiers, the former Northern Ireland secretary, said: “It is vital that the government uses this as an opportunity to talk quite toughly with the EU about how the Northern Ireland protocol is working. “We’ve seen the EU make a massive misjudgment. This is an important time for us to point out some of the other really serious defects in how it is approaching Northern Ireland. That’s certainly the message that a lot of my colleagues have for Michael Gove and for the prime minister as well. I certainly want the protocol to be a temporary arrangement, but we can now turn it into something that is broadly workable.” David Jones, a Brexiter and former Tory cabinet minister, said: “The protocol must go. The EU have shown how ready they are to weaponise it, even with no provocation, in a fit of spite. We have to put more sensible measures in its place.” Gove said on Saturday he was seeking to “reset” relations with the EU over Northern Ireland. He also said while the UK’s vaccine supply would be unaffected, the government would seek to help other European countries, if it was in a position to do so. The compromise eventually agreed between the European commission and Dublin exempts vaccine manufacturers from seeking authorisation for doses crossing the border to Northern Ireland, avoiding claims of erecting a vaccine border in Ireland. The Irish government will instead be required to report on the quantity of doses distributed to Northern Ireland in a sign that the commission remains concerned that it could be a backdoor route for the movement of vaccines to the rest of the UK. An EU official said: “We have also got suspicions that certain vaccinations are leaving Europe instead of coming to us, so we have put in place this mechanism to check.” Officials said on Saturday they remained determined to hold manufacturers to account, with vaccine shortages being reported across the bloc. It is in dispute with AstraZeneca after the company said it could only deliver a fraction of the vaccines initially promised. “We have a serious issue with a company that has signed a contract with us saying that it was to put at our disposal vaccines from two factories from the UK – and has not delivered a single dose from those factories,” an EU official said about AstraZeneca. “And it was clearly saying, supported by the British government, that those factories will not be delivering vaccines to the EU until the UK has got the 100 million doses it is supposed to get. This is a serious issue for us.” AstraZeneca has said that it has a contractual obligation to fulfil the UK’s order of 100 million doses from the plants in Oxford and Staffordshire before diverting vaccine to the EU.