Millions of doses of coronavirus vaccine could be blocked from entering Britain from the EU within days after Brussels said it had to respond to shortages emerging in member states. Following reports of a lack of doses across the bloc, the European commission announced plans to give national regulators the power to reject export requests. The development raises concerns over the continued flow of the Pfizer/BioNTech vaccine, for which the UK has a 40m-dose order, from its plant in Belgium. “There is a possibility in certain circumstances not to allow the export to come forward,” an official said. “Indeed, that would be the final option.” Should the UK become reliant on home-produced vaccines, securing herd immunity through the vaccination of 75% of the population could be delayed by nearly two months from 14 July to 1 September putting thousands of lives in danger, according to analysis by the data analytics firm Airfinity shared with the Guardian. The European federation of pharmaceutical industries and associations warned that the commission plan could lead to a breakdown of global supply of vaccines. “Global supply chains are key to delivering vaccines to protect citizens … Risking retaliatory measures from other regions at this crucial moment in the fight against Covid-19 is not in anyone’s best interest,” the industry group said. The 27 EU member states were devastated by the announcement last week by the Anglo-Swedish pharmaceutical company AstraZeneca that it would only be able to deliver 25% of the 100m doses expected by the end of March, citing production problems in its Belgian plant. The Oxford/AstraZeneca vaccine is expected to be authorised for use by the European Medicines Agency on Friday and advance orders of the doses were considered key to the bloc’s vaccination strategy. The company’s assurances to the UK government that it would fulfil its order of 2m doses a day without delay further fuelled the anger felt by officials involved in the EU’s faltering programme. Just 2% of the EU adult population has received a vaccine jab, compared with 11% of those in the UK, with scant sign of the bloc’s vaccination drive gaining momentum. The lack of doses in the EU has already forced the Spanish government to announce a temporary pause in its rollout of the vaccine in Madrid, and to warn that Catalonia could follow. The public health agency for Paris and the surrounding region, an area with a population of 12.1 million people, informed hospitals on Thursday that it would suspend its programme from 2 February. Hospitals in the Hauts-de-France region in northern France were told that the deployment of first doses there would be delayed to the first week of March. Germany’s health minister, Jens Spahn, said he feared “at least another 10 tough weeks” of shortages. “Making vaccines is very complex, and there can be a need for building work to increase capacity that leads to delays,” Spahn said on NDR radio. “But then it has to impact everyone in the same way and not just the EU.” With national vaccine plans in tatters, and AstraZeneca refusing to divert doses made at sites in Oxford and Staffordshire to the EU, Brussels has been seeking other means of securing its supply. In a letter on Thursday, the president of the European council, Charles Michel, welcomed the commission’s plan, adding that the EU had to “explore all options and make use of all legal means and enforcement measures at our disposal under the treaties”. He added: “While continuing dialogue, I believe the EU needs to take robust action to secure its supply of vaccines and demonstrate concretely that the protection of its citizens remains our absolute priority.” Officials said they hoped there would be no need for export bans but conceded that a block on the export of vaccines, such as that produced by Pfizer/BioNTech in Belgium for the UK, was possible. The British government’s decision to ban the export of certain coronavirus medicines was further cited by an EU official as reason for Brussels to protect itself from acts of protectionism around the world. “In an ideal world … the whole story of vaccination would run smoothly without any problems. But unfortunately we are not in an ideal world,” the official said. “We have seen that when it comes to the shortage of vaccines, when it comes to the export of vaccines … there are obviously deficiencies. “That’s why, and given the circumstances with certain states around the world, even in our neighbourhood, acting in terms of restrictions of exports, even banning exports for certain products, I think we need to be upfront, and we need to react.” The full criteria for blocking exports will be published on Friday, with adoption of the export authorisation mechanism expected within days. “Time is of the essence,” an EU official said. Peter Liese, a German MEP in Angela Merkel’s CDU party, said: “If the only solution is to have a reduction of the delivery to the UK, and that would bring more vaccine to the EU, that is only fair.” AstraZeneca has said it is contractually obliged to fulfil its contract with the UK before diverting doses from its British plants to the EU. The Cabinet Office minister, Michael Gove, said the UK would only help the EU with doses if there were spare vials. “We will want to talk to and with our friends in Europe to see how we can help,” he said. “But the really important thing is to make sure our own vaccination programme proceeds precisely as planned.” The development came as Belgian regulators launched an investigation into AstraZeneca’s coronavirus vaccine production site 25 miles (40km) south of Brussels, in Seneffe, at the request of the commission. Officials believe a significant number of vaccine doses made in Belgium have been transported to the UK and that this has contributed to the shortages. An EU official said: “We discussed this matter with our Belgian colleagues. We want to see whether what we’re being told is correct or not. So I would like to thank the Belgian authorities for undertaking these efforts.” A spokesperson for the Belgian health ministry said the inspections at the plant were being conducted to “make sure that the delivery delay is indeed due to a production problem on the Belgian site”. The EU is investing €336m (£297m) in AstraZeneca in return for 400m doses. But not all of the money has been paid to the pharmaceutical company. EU lawyers are examining whether there has been a breach of contract.