Britain on Sunday warned the European Union against halting exports of AstraZeneca's Covid-19 vaccines if the bloc does not receive promised deliveries, saying such a move would be "counter-productive".
Defence Secretary Ben Wallace said "the world is watching" how the EU responds to a shortfall in deliveries of the vaccine from the Anglo-Swedish pharma giant, and that Brussels' reputation was at stake.
His comments came after EU chief Ursula von der Leyen again threatened Saturday to impose an export ban on the AstraZeneca vaccine unless the company delivers more of the 90 million doses it agreed to supply in the first quarter of 2021.
The row is increasingly focused on a factory in the Netherlands that is still awaiting official approval, but where both sides are claiming the future supply of the AstraZeneca jab and of key ingredients, EU and UK sources said.
Appearing on several political talk shows, Wallace said trying to "balkanise or build walls" around vaccine production would damage both British and European citizens.
"If contracts get broken, and undertakings, that is a very damaging thing to happen for a trading bloc that prides itself on the rule of law," he told Sky News.
"It is counterproductive because the one thing we know about vaccine production and manufacture is that it is collaborative.
"They would undermine not only their own citizens' chances of having a proper vaccine programme, but also many other countries around the world with the reputational damage for the EU which they would find very hard to change over the short-term."
Shortfall from India
The ongoing cross-Channel row over the AstraZeneca vaccine comes as Britain's inoculation campaign hits new heights, while the EU struggles with its own rollout and a third virus wave prompts renewed curbs on public life.
The EU is "simply trying to have the contract with AstraZeneca respected," a source close to von der Leyen told AFP.
"The company has delivered less than 10 percent of the planned doses for 2021. It is therefore normal for us to ask that these doses be delivered as planned to Europeans," the source added.
The British government this weekend hailed its vaccination programme as "a huge success" after announcing that half of the adult population — nearly 27 million people — have received a first dose.
The country administered a record 711,156 vaccinations in a single day on Friday.
However, a supply shortfall from the Serum Institute of India — the world's biggest vaccine maker — means the rollout's next phase covering people in their 40s will be delayed from April until May.
In contrast Europe has struggled with its jabs campaign. Von der Leyen said AstraZeneca had delivered only 30 percent of the 90 million vaccine doses pledged in the first quarter.
Brussels is furious the firm has appeared to been able to deliver on its UK contract while falling short on the continent.
The company has blamed production delays at its EU plants, while Britain has noted its jabs come from a number of sources outside the continent.