The European Commission is working on legal proceedings against AstraZeneca after the drugmaker cut COVID-19 vaccine deliveries to the European Union, according to sources familiar with the matter. 

An EU official involved in talks with vaccine makers told Reuters on Thursday that a story by Politico on the matter was correct. "EU states have to decide if they (will) participate. It is about fulfillment of deliveries by the end of the second quarter."

The Anglo-Swedish drugmaker has been under fire in the trading bloc for cutting supplies several times to levels much lower than promised, and potential legal action had been discussed previously.

There was no immediate response from AstraZeneca on Thursday to a request for comment.

Under its contract with the EU, the company had committed to delivering 180 million vaccine doses in the second quarter. 

Chief Executive Pascal Soriot told a hearing of the EU parliament in February that he hoped to meet EU expectations on deliveries in that period.

Politico reported the latest possible legal action citing five unnamed European Union diplomats, adding that at a meeting of ambassadors on Wednesday a majority of EU countries said they would support suing the company.