The UK government has ended its Covid vaccine deal with Valneva, according to the French company.
It had put in an order for 100 million doses, after requesting 40 million more in February.
But Valneva said the deal has now been terminated.
The government served notice over allegations of a breach of the agreement, which the French pharmaceutical company “strenuously” denies.
The Valneva jab is still in the clinical trial phase.
The French firm said it could be approved for use, subject to trial results and a decision from the UK medicines regulator, towards the end of this year.
Valneva said on Monday it had “received a termination notice from the UK government (“HMG”) in relation to the Supply Agreement for its Covid-19 vaccine candidate, VLA2001”.
A company statement said: “The contract provides HMG with the right to terminate. HMG has alleged that the Company is in breach of its obligations under the Supply Agreement, but the Company strenuously denies this.”