The Court of Appeal has upheld the case of a French workers’ union against the closure of cross-Channel ferry service MyFerryLink.

Judges backed the challenge made by the SCOP today, who were fighting a ban on the operator handed out by the Competition and Markets Authority earlier this year.

The ban followed an investigation into Eurotunnel’s ownership of the service, which officials said broke monopoly rules, giving the Channel Tunnel operator more than 50% of the cross-Channel market.

Judges voted to uphold the SCOP’s appeal by two to one today, potentially averting the loss of 600 jobs at the company.

Eurotunnel has been looking to sell the service but would have been forced to close it by the end of July if a buyer had not been found.

The SCOP’s case hinged on the manner in which Eurotunnel took control of MyFerryLink’s three ships, which formerly belonged to SeaFrance, the ferry operator which went into liquidation in 2012.

“The decision of the Court of Appeal is very comprehensive, exposing fatal flaws in the CMA’s analysis..." - Raphael Doutrebente, MyFerryLink

The SCOP, which is employed to run MyFerryLink by Eurotunnel on its behalf, and is made up mainly of former SeaFrance workers, said the purchase of the ferries should be treated as an acquisition and not a merger under UK merger control rules.

The Competition and Markets Authority said it has noted today’s judgement and will study it carefully before considering its next steps.

The victory has been seen as a vindication by the SCOP – fully known as Société Coopérative de Production de SeaFrance S.A – in the long-running legal saga, with owners Eurotunnel appearing to have given up following last the CMA ruling in January.

It began when rival operators DFDS and P&O Ferries complained to the Office of Fair Trading following the Folkestone company’s acquisition of the SeaFrance ferries in 2012.

The case was refered the CMA, then known as the Competition Commission, and a lengthy series of rulings and counter rulings has followed.

MyFerryLink director Raphael Doutrebente said: “The decision of the Court of Appeal is very comprehensive, exposing fatal flaws in the CMA’s analysis.

“The decision represents a significant victory both for our dedicated employees and for our customers, who will continue to benefit from healthy competition on the short sea route.

“This should now spell the end of the road for the CMA’s attempts to suppress the MyFerryLink business, which has always sought to deliver a high quality and reliable service for its customers.”