Eurotunnel will begin its latest appeal against a ruling forcing it to close its ferry business MyFerryLink today.

The Channel Tunnel operator will appear before the Competition Appeal Tribunal to explain why its Dover to Calais service should be allowed to continue.

The Competition and Markets Authority ruled in June that it was right to say the Folkestone-based company has to stop operating ferries on the route.

Eurotunnel launched the service in August 2012 after acquiring three vessels which previously belonged to SeaFrance, before the company went into administration.

The appeal, which is expected to last two days, centres on a legal point of whether the Competition and Markets Authority has a right to rule on the case at all.

Eurotunnel will argue its ownership of the ferries constitutes an acquisition of assets, rather than a merger, thus not breaking monopoly rules.

A judgement is not expected for at least a month but should the original decision be upheld, MyFerryLink will be forced to close within six months, putting 600 jobs at risk.

This timetable has been hanging over workers since the ruling in June but was suspended when Eurotunnel launched its appeal.

The Competition and Markets Authority banned MyFerryLink from running services from Dover because it believes it will force rival operators on the route out of business.

Deputy chair Alasdair Smith said: “With two of the operators on the Dover–Calais route making substantial losses, it remains our view that the current level of competition on the route is unsustainable and likely to lead to the exit of a competitor.

“That will leave Eurotunnel, which is funding MyFerryLink’s current losses, as one of only two ferry operators in addition to owning the competing rail link.

“Eurotunnel’s purchase of the ferries means it now has over half the market and its share will rise further if competitors exit.”

The legal saga began following an original ruling by the Competition Commission in June 2013, which said Eurotunnel’s ownership of MyFerryLink gave it too much share of the cross-Channel market.

Eurotunnel will be allowed to find another owner for the MyFerryLink business, if that made it completely independent.

“With two of the operators on the Dover–Calais route making substantial losses, it remains our view that the current level of competition on the route is unsustainable and likely to lead to the exit of a competitor..." - Alasdair Smith

The company appeared to admit it is resigned to defeat in an announcement on the London Stock Exchange in September.

In a release entitled “Groupe Eurotunnel Notes the Determination of the Competition and Markets Authority to Ban MyFerryLink”, it indicated the uncertainty was putting future contracts for the ferry operator in jeopardy and it would be unlikely to appeal again.

It said: “This position confirms in Groupe Eurotunnel’s opinion the unalterable determination of the CMA to bring to an end the activities of MyFerryLink.

“As such, and under the hypothesis that the Competition Appeal Tribunal (CAT) simply remits its judgement to the CMA, as it did in December 2013, Groupe Eurotunnel would have to reflect on the possibility of continuing to support the activity.

“The order published today could weigh heavily on the forthcoming annual contract negotiations between MyFerryLink and the major cross-Channel freight transporters.

“Groupe Eurotunnel strongly regrets the position that the CMA holds and its inevitable consequences.”