A contract between Brussels and AstraZeneca for its COVID-19 vaccine contains binding orders, EU chief Ursula von der Leyen has said.
Her comments come amid the deepening row with the drug giant over supply shortages, as European regulators are poised to approve the coronavirus jab.
The contract between the EU and the pharmaceutical firm was published on Friday morning, as the bloc searches for answers over the vaccine shortfall.
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EU pressures Astra Zeneca over shortfall
The threat of legal action has been raised by the EU to secure COVID-19 vaccine stocks if talks over delayed deliveries fail.
Brussels has demanded doses be sent from UK plants to make up for a shortfall, but Cabinet Office Minister Michael Gove said the government will not allow vaccines intended for Britain to go to the bloc.
On Friday, an EU source said AstraZeneca has offered an additional eight million COVID-19 vaccine doses in the first quarter this year.
The EU also plans to tighten oversight of vaccine exports.
Brussels has faced criticism and growing public frustration over the slow rollout of jabs as the UK, which is looking to approve its fourth vaccine, has raced ahead.
Ramping up the war of words, Ms Von der Leyen told German radio the best-effort delivery clause in the contract was only valid as long as it was not clear whether AstraZeneca could develop a vaccine.
She said the deal contained very clear delivery amounts for December and the first three quarters of 2021, and also mentioned four production sites, two of which are in Britain.
“There are binding orders and the contract is crystal clear,” she said.
Meanwhile, European Council President Charles Michel has also said the EU should consider legal means to ensure supplies.
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Mr Michel, who represents the EU’s 27 member states, said in a letter to a number of national leaders: “So far the explanations provided by some pharmaceutical companies have not provided us with the reassurances we need.
“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.
“In this regard, I welcome the commission’s proposal for an export transparency mechanism which could be an instrument to ensure that vaccine doses originally intended for member states are not unduly exported.
“In addition, I support all efforts to resolve the matter with companies through dialogue and negotiation.”
He added: “However, if no satisfactory solution can be found, I believe we should explore all options and make use of all legal means and enforcement measures at our disposal.
“I believe this solution would demonstrate the EU’s strength and reliability in protecting its citizens’ health over and above all other considerations.”
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