Chris Grayling has been accused of trying to conduct large parts of a trial over the £14m Brexit ferry fiasco in private, against the principle of open justice, the high court has heard.

The transport secretary is being sued by Eurotunnel over the allegedly unlawful award of a government contract to Seaborne Freight, a company with no ships, and two other ferry companies, in a case due to start on Friday.

Lawyers for Eurotunnel told the high court on Monday that the minister was trying to keep the majority of documents in relation to the contract out of the public domain. They said they did not know his reasons but argued that if Grayling was trying to avoid adverse publicity or embarrassment then this was not legally justifiable.

No-deal Brexit ferry company owns no ships and has never run Channel service Read more

“It appears … that the secretary of state is seeking to maintain extensive claims to confidentiality in relation to large numbers of disclosed documents and appears to intend that large parts, if not all, of the trial should be held in private,” Eurotunnel said in a submission.

The company’s lawyers said Grayling’s approach was unjustified and they reminded lawyers for the Department for Transport (DfT) that the judge Mr Justice Fraser had previously told them the court was “not a marketing or PR department for any litigant and the principle of open justice is an important one”.

Eurotunnel claimed Grayling’s “conduct in this case is far removed from that which would be expected by a responsible [public body] defendant engaged in high profile and urgent litigation”.

The lawyers told the judge it was clear the vast majority of the material that had been disclosed to them about the Seaborne contract was not confidential and should be available for public scrutiny.

“It may be that the material is perceived by government to be profoundly embarrassing and it would naturally prefer that it is not in the public domain. That would be, of course, an entirely irrelevant consideration in relation to matters of confidentiality,” the lawyers for Eurotunnel said.

The DfT was ordered to review all 8,000 documents that had been disclosed in the case and to return to court by 4.30pm on Thursday with its legal justification for its desired confidentiality.

Eurotunnel, which operates the Channel tunnel, is arguing that ferry contracts totalling £108m were awarded to Seaborne and two other firms through a “secretive and flawed” procurement process.

Grayling cancelled the contract with Seaborne this month after it emerged that the company had no contract with the ports involved in the proposed new ferry route between Ramsgate and Ostend.

The DfT said it could not comment on ongoing proceedings. In its submissions to the court, it said the scale of disclosure was far greater than anticipated, running to 10,000 documents.

It said the burden of disclosure was far greater on the defendant and the process was “extremely time consuming” given the necessary reviews, before submission, of legally and personally sensitive data.

The DfT argued it would make the documents available confidentially until the documents relevant to the trial were identified. It said that the legitimate need for confidentiality could not be jettisoned simply because the trial was fast-tracked.