EU member states and the European Commission are suing the pharmaceutical company after it delivered only 30 million doses in the first quarter of 2021 and not the 120 million it was contracted to supply.
While the pace of delivery has since picked up, only about 70 million of the 180 million doses promised for the second quarter are expected.
"AstraZeneca did not even try to respect the contract," the EU's lawyer Rafael Jafferali told a Brussels court.
AstraZeneca has previously said the contract was not binding because it committed only to make "best reasonable efforts" in delivering vaccines. The company insisted it abided by the agreement.
But Mr Jafferali said that principle had not been adhered to because 50 million doses that should have been delivered to the EU went to other countries instead.
That includes inoculations produced in the UK, which AstraZeneca said were reserved for Britain under the terms of a deal agreed by the government in London with the University of Oxford, the vaccine’s developer.
Mr Jafferali said AstraZeneca had agreed in its EU contract that other responsibilities would not prevent it from abiding by the terms of the deal.
Charles-Edouard Lambert, another lawyer for the EU, said AstraZeneca decided to reserve production at its Oxford site for Britain.
“This is utterly serious. AstraZeneca did not use all the means at its disposal. There is a double standard in the way it treats the UK and member states," he said.
Hakim Boularbah, a lawyer for AstraZeneca, said the company's deal with the UK government and Oxford to supply 100 million doses of vaccine at cost price clearly gave priority to Britain. “It’s very shocking to be accused of fraud,” Mr Boularbah said. He called it “a groundless accusation.”
AstraZeneca said it had told the European Commission that the UK manufacturing chain would firstly be dedicated to British supplies.
Mr Jafferali said the EU was seeking €10 ($12.23) for each day of delay for each dose as compensation and an additional €10 million for each breach of the contract that the judge identifies.
AstraZeneca was also accused of failing to provide sufficient data on reasons for delivery delays.
“The information provided by AstraZeneca did not allow us to fully understand the situation before mid-March 2021,” Mr Jafferali said.