image caption"EU vaccines war explodes" is the headline dominating the front of the Daily Mail, as the paper joins several others to lead with Brussels' decision earlier on Friday to add controls on the export of jabs to the UK. The EU, which has since backtracked, wanted to stop Northern Ireland being used as a backdoor to the rest of the UK, amid concerns over the supply of the Oxford/AstraZeneca vaccine on the continent. The EU Commission originally invoked Article 16 of the Northern Ireland Protocol, which allows parts of the Brexit deal to be overridden.
image captionThe Daily Mirror says the EU had cited "questionable behaviour" by UK-based vaccine manufacturers.
image captionIn an interview with the Guardian and a small group of other media, French President Emmanuel Macron suggested that the drugs firm AstraZeneca may have over-delivered to Britain and warned that the EU will seek to "control" vaccine exports from the bloc. He said the vaccine appeared to be "quasi-ineffective" in those over the age of 65, but acknowledged he did not have any official information to support the claim, the paper reports.
image captionBut senior Conservative MPs and scientists have accused the French president of making "nonsense" and "untrue" claims about the Oxford/AstraZeneca vaccine, the Daily Telegraph reports. Mr Macron has claimed that the vaccine "doesn't work as expected". Sir John Bell, regius chair of medicine at the University of Oxford who led the vaccine trials, told the paper: "Perhaps he [Mr Macron] is trying to reduce demand for the vaccine for some reason."
image captionMeanwhile, the EU's chief Brexit negotiator Michel Barnier has told the Times that he wants a "spirit of cooperation" between Brussels and the UK. "I believe that we must face this crisis with responsibility, certainly not with the spirit of one-upmanship or unhealthy competition," Mr Barnier told the paper.
image captionThe Financial Times Weekend also carries the escalating row between the EU and UK, describing the bloc's actions as "incendiary". For its lead story, the FT focuses on the US stock trading battle between amateur private investors and hedge funds over the retailer GameStop.
image captionElsewhere, some MPs have told the Daily Express that EU chiefs were exhibiting "mafia type behaviour" over the Covid vaccine exports.
image captionThe Sun quotes former Tory leader Iain Duncan Smith accusing the EU of "childish and arrogant" behaviour.
image captionStriking a more optimistic tone, the i weekend says: "Vaccine leap will protect UK - and rest of the world." Reporting on the single-dose Johnson and Johnson vaccine, which could "transform prospects for fighting Covid-19", the paper says no one from the clinical trial required hospitalisation or died from the virus. There are 30 million doses scheduled for delivery to Britain during the first half of this year, the paper adds. Some 7.9 million people in the UK have received their first jab - 11.8% of the population.
image captionAnd the former head of the UK Vaccine Taskforce Kate Bingham is celebrating the Novavax jab - which has been shown to be 89% effective in large-scale UK trials - and has ditched Dry January, the Daily Star reports.