The cargo vessel that blocked the Suez Canal, holding up world shipping, is grounded again, says a law firm battling to help its client off-load impounded containers.

The Egyptian authorities have detained the Ever Given claiming 550 million US dollars (£395 million) in compensation from the ship’s owners Shoei Kisen Kaisha, following the operation to free the massive vessel which ran aground in March.

Jai Sharma, a partner and head of cargo casualty with law firm Clyde & Co, has written an open letter to the Suez Canal Authority (SCA) seeking to resolve the dispute on behalf of his company’s clients.

He wrote: “We represent the insurers of over 100 million (dollars) of cargo on board. Some of this cargo is time-sensitive and the delay is causing many cargo receivers losses and operational difficulties at a time when many businesses have been under pressure because of the pandemic.”

Mr Sharma added: “Whilst we understand that the SCA have informally reduced their demand to 550 million dollars from the initial 916 million dollars, in our view this remains a grossly excessive sum for the services rendered and the losses claimed by the SCA.”

The Ever Given was carrying around 700 million dollars (£500 million) in cargo between Asia and Europe when it ran aground in the Suez Canal on March 23.

The maritime crisis clogged one of the world’s most vital waterways and the vessel was eventually freed by salvage teams six days later.

The latest in a series of court hearings is scheduled for Sunday but Mr Sharma does not believe it is likely a conclusion will be reached then, and discussions are likely to continue between the parties.

It is understood 150 million dollars has been offered to settle the claim, but the SCA is still seeking 550 million dollars.

Speaking to the PA News agency, Mr Sharma said the claim amount was “unprecedented” adding: “It’s far, far more by a factor of ten or twenty then we would have expected.

“I think people are willing to pay a reasonable sum and they’re even willing to pay more than a reasonable sum just to resolve it, but we think this is multiples of an unreasonable sum.”

The Ever Given is carrying around 18,000 shipping containers filled with an array of items from summer goods like barbecues, swimwear and sun loungers to items with a limited shelf life like bamboo shoots, bean curd and lemons.

It is moored in the Great Bitter Lake which is part of the Suez Canal with its crew still aboard.

The UK Club, one of the insurers of the Ever Given, said in a statement on its website: “The UK Club reports that, on authority from the owner and together with the ship’s other insurers it is currently engaged in serious and constructive negotiations with the Suez Canal Authority regarding the Authority’s claim arising from the grounding of the Ever Given, and is hopeful of a positive resolution to these negotiations in the near future.”

The Suez Canal Authority has been contacted for a comment.