John Swinney has described the decision to close the Grangemouth refinery as “premature” and said more time is needed to put options for the site in place.

Speaking at First Minister’s questions, he said he supported SNP backbencher Michelle Thomson’s call for a pause in the process.

He said he had asked the Prime Minister to work with the Scottish Government and the refinery owner Petroineos to avoid closure before all options have been considered. Petroineos plans to shut the plant next summer with the loss of 400 direct jobs.

Ms Thomson referred to doubts raised by the Unite union yesterday on the company’s accounts and its claim that the plant was profitable.

Mr Swinney said he wanted to “avoid economic disruption and damage to the Grangemouth area and especially the livelihoods of the workers involved.”

Conservative Stephen Kerr noted that Project Willow, the initiative focused on the future of the site, will not report until later next year and asked if an interim report could be produced.

Mr Swnney said he could not commit to an early report as more time was needed to consider proposals, including the Acorn carbon capture and storage project. He had told the Prime Minister that he was disappointed that this was not mentioned in the Chancellor’s Budget.

Ash Regan, the Alba MSP, said Scotland would become the only top 25 oil producing nation with no refining capacity. She asked: “How has it come to this, that a nationalist government looks away helpless as key national infrastructure is lost forever?

Mr Swinney replied: “I don’t think Ash Regan has listened to a word I have said in response to Michelle Thomson or to Stephen Kerr.

“I am actively pursuing an option to maintain refining capacity at Grangemouth. If that needs to be stated again, I will state it again in parliament so it is clearly understood because economic damage will be done if there is not intervention to prolong the refinery life cycle at Grangemouth.

“If we do that we have the opportunity to secure carbon capture and storage, we have the opportunity to take forward the other projects through the Project Willow exercise and that will provide us with a secure future for the Grangemouth site.

“So let there be no doubt about it, the Scottish Government is actively pursuing these opportunities to protect the workers at Grangemouth.”

He said the Energy Secretary last met with Petroineos on 5 November and government officials met the firm last week.

Michelle Thomson said the company’s accounts are distorted and there is no case for closure.