Boris Johnson is expected to speak to his EU counterparts this week as a row over Covid vaccine supplies continues.
EU leaders will hold a virtual meeting on Thursday to discuss a ban on Oxford-AstraZeneca vaccine exports to the UK – but the PM aims to put the UK’s case in one-on-one phone calls before that.
The European Commission president says the EU can “forbid” vaccines made on the continent being sent to the UK.
But a government minister said it was crucial the EU honours its commitments.
Downing Street said European Commission President Ursula von der Leyen told Mr Johnson earlier this year that the EU was not intending to restrict exports of vaccines.
Helen Whately, health and social care minister, urged the EU to stand by this commitment and warned against “vaccine nationalism and protectionism”.
The latest flashpoint appears to be over doses made in a Dutch factory.
Meanwhile, the long-awaited results of the US trial of the Oxford-AstraZeneca vaccine, which involved more than 32,000 volunteers, show that the jab is safe and highly effective.
Several European leaders paused rollout of the vaccine amid concerns of a possible link with blood clots. UK and EU regulators said there was no evidence the vaccine causes blood clots.
European leaders have faced criticism for the slow pace of the vaccine rollout on the continent.
Less than 12% of the EU’s population is reported to have received the vaccine, compared with nearly 40% in the UK.
The EU has encountered production problems with the Pfizer-BioNTech, Moderna and Oxford-AstraZeneca vaccines.
British-Swedish manufacturer AstraZeneca said the fact that EU contracts were signed later than with the UK caused problems with supplying their vaccine.
Downing Street has previously said that it does not believe that vaccine supply issues will affect the current road map for easing lockdown restrictions.
Ms Whately told BBC Breakfast the UK was “on track” to meet its target of offering the vaccine to the top nine priority groups by 15 April and to all adults by the end of July.
There is also enough supply to ensure people have their second doses, she added.
“We always knew that there could be ups and downs in supply but we have a… diverse supply chain and we are absolutely determined to keep on deploying the vaccine,” she said.
But the Guardian says a report by data analysts Airfinity suggests that if an export ban was applied to all vaccines – including those from Moderna and Johnson & Johnson that have yet to be deployed in the UK – it would see the offer of a first vaccine to every adult completed in late August rather than the target date of 31 July.