THE EU and the UK are currently at the precipice of a fierce and potentially ugly battle over Covid-19 vaccines.
Tensions between the unions are sky-high with British Prime Minister Boris Johnson and European Commission president Usula von der Leyen trading warnings and veiled threats.
But what's actually going on and who's in the right?
Here's everything we know:
AstraZeneca supply issues
The main problem began when AstraZeneca - a British-Swedish pharmaceutical company - ran into major vaccine supply issues.
Despite agreeing deals to distribute its vaccines all over the world, including to the EU and to the UK, the company announced earlier in the year that it wouldn't be able to deliver on its initial promises.
As such, AstraZeneca reduced the amount of doses it would initially send to the EU.
UK vaccine success
The UK's vaccination programme has been one of the world's swiftest and most efficient. Only Israel and the United Arab Emirates have administered vaccines to a higher percentage of their population. As of this week, some 28 million Brits have been given at least one dose of the Covid-19 vaccine.
The UK was able to get out in front because, unlike EU nations, they weren't beholden to the European Medicines Agency (EMA) to approve vaccines for use. In early December, the UK became the first country in the world to clinically approve a Covid-19 vaccine for use, and their roll-out has gone from strength to strength since then.
Because of this, however, the powers that be within the EU feel as though, in the wake of AstraZeneca's supply issues, it isn't fair that their vaccine supply should suffer, while the UK's remains relatively unscathed.
President von der Leyen infamously triggered article 16 of the Northern Ireland Protocol last month in an attempt to restrict the flow of vaccines to Britain over the Irish border.
The short-sighted decision, which would have created a hard-border on the island of Ireland, was widely criticised and revoked that same day.
EU blocking vaccines
The row between the EU and the UK has centred around a factory in the Netherlands, which has promised supplies of the AstraZeneca jab to both the UK and the EU, but is not yet an approved supplier to either so none of its goods can be used yet.
It's understood that up to 10 million doses of the vaccine could be up for grabs from the site, and both the UK and the EU claim that they have rights to it.
European chiefs are threatening to shut down exports to the UK if they don't get access to the spare vaccines in Holland, regardless of any agreement made between the site and the UK.
The European Commission said last week that it would restrict exports of vaccines to countries that don't reciprocate or that already have high vaccination rates. The UK is the largest recipient of doses made in the EU, receiving 10 million of 42 million shots from the bloc so far.
"We didn’t get anything from the Brits while we are delivering vaccines to them," Ms von der Leyen said.
She also confirmed that the EU is considering rejecting export authorisation on jabs bound for the UK until AstraZeneca coughs up its share of vaccines purchased by the EU.
Von der Leyen warned on Saturday: "We have the possibility to ban planned exports. This is a message to AstraZeneca: You fulfil your part of the deal toward Europe before you start to deliver to other countries."
The EU, which has pledged to immunise 70% of adults by the end of September, is struggling to overcome a slow start to its inoculation campaign. The bloc has administered 12 doses per 100 people, less than a third of what the U.K. has managed, according to Bloomberg’s Coronavirus Vaccine Tracker.
Reaction from UK
The UK claims that it's owed the vaccine its has purchased and that the EU has now right to keep the vaccines for themselves, but it's understood that Prime Minister Boris Johnson is attempting to extend an olive branch.
Reports circulating on Monday suggest that the UK is willing to share millions of doses with the EU as a peace offering and an attempt to defuse the tension.
Mr Johnson warned that "previous experience has taught us that when a wave hits our friends, it washed up on our shores as well," and suggested that the best way to protect the UK, was to protect its neighbours too.
Mr Johnson and Commission President von der Leyen spoke last week and a new round of high-level diplomacy is expected among leaders ahead of a summit in Brussels.