The deal, signed with chief supplier CF Industries, will see the flow of CO2 extended until early 2022. The US firm stated that the planned extension should allow the government more time to find alternative sources in the new year.

The extension comes following the suspension of CO2 production by CF Industries at its two sites in Cheshire and Billingham last month. The Billingham site was later reopened as the government stepped in, agreeing to meet the costs of running it for three weeks.