A concrete wall six metres high and 600 metres long is needed to prevent refugees and migrants from entering the Channel tunnel at Calais, according to Eurotunnel.

The company is asking the British and French governments to foot the €6m (£4.6m) bill for the work, as well as reimbursing €29m (£23m) in lost revenue and costs from last year.

Eurotunnel said it expected even more migrants to attempt to reach the UK this summer, and has called for a joint control centre linking police, border guards and security staff to be implemented swiftly in preparation.

The operator of the tunnel linking the UK with France said disruption at Calais affected its truck and passenger shuttle services in the second half of 2015. Announcing its annual results, it said: “The security of the fixed link being the responsibility of the two governments, a claim for €29m has been made via the intergovernmental commission to compensate essentially the revenue losses due to migrant pressure.”

The chief executive, Jacques Gounon, said the Treaty of Canterbury made the states’ obligations clear, but said Eurotunnel was still shouldering additional costs for what was a question of public security. He said that while measures taken by Britain and France had meant there had been no disruption or breaches since late October last year, “I regret that when I asked for reaction in the first half [of 2015] I could not persuade the state that action was needed.”

He said he expected the governments to “find a suitable gentleman’s agreement” over the compensation bill, adding: “What is important that it is a long-term relationship and what happened before the state reaction is absolutely clear. Traffic in January and February has shown that it is not an issue now.”

But, he added, both governments needed to do more and spend more to maintain the tunnel’s security: “There is a risk of course: we know that millions of migrants could overwhelm Europe this summer and some could go to Calais. We want the funding to be one step in advance of any new migrant invasion.

“I would not like to be in the same position [this year] … It would be better to anticipate a new invasion of migrants this summer. This is a long term issue and we need to be prepared.”

The concrete wall would extend the mouth of the tunnel 600m further into France along the Eurostar tracks, which have been identified as a potential weak spot to breach the tunnel security.

Eurotunnel carries Eurostar high-speed trains between Paris, Brussels and London, and shuttle trains containing passenger cars, coaches and freight trucks.

The company suffered disruption to its services starting in the summer from refugees and migrants, 6,000 of whom now live in the makeshift camps outside Calais known as the Jungle. The €29m claim mainly covers reduced revenue but also includes the cost of paying employees for extra shifts.

People trying to stow away on trains bound for the UK forced rail operators to suspend night-time services on and off from June to October, causing the number of trains running through the tunnel last year to fall 17% to 2,421. The number of people trying to board trains illegally fell dramatically after Britain funded fences in Calais and France deployed extra police, Eurotunnel said.

“The work done in co-operation with the British and French governments ... has enabled Eurotunnel to provide a transport service with no disruption since October 2015,” the company said.

Eurotunnel’s services were also affected by the terrorist attacks on Paris in November, which hit cross-channel coach travel as well.

For the year to the end of December, operating profit rose 2% to €387m from revenues of €1.2bn, up 5%. Eurotunnel transported 2.6m passenger vehicles and 1.5m trucks.

The company increased its 2015 dividend by 22% to 22 cents and forecast a further rise in profit this year and next, driven by higher economic activity on both sides of the channel.

