A cluster of supertankers anchored off the Suffolk coast has fuelled fresh fears about the potential for pollution on the beaches of one of the country’s best-loved resorts.

Fifteen crude oil tankers have been sitting close together between 10 and 15 miles off the coast at Southwold – an area designated by Government as a zone for ship-to-ship transfers.

Southwold Town Council has asked ministers to reconsider policy because it says pollution is already occurring due to the activities.

Prof Michael Rowan-Robinson, Southwold and Reydon Society president, said: “We have been monitoring and assessing the situation, and have become increasingly concerned.

“It’s very noticeable. You can see the lights of those closer to shore at night, and there are more over the horizon.

“The town council wrote to the minister after the previous election, asking the government to reconsider its policy, because it’s a threat hanging over the coast. They should not be there.

“What’s not clear is whether or not ship-to-ship oil transfers are taking place – but even parking there alone is not sustainable for the heritage coast.”

Protesters waged a campaign to prevent the area of North Sea being designated for ship-to-shore transfers. The last Labour government drafted regulations banning offshore transfers so that ships used ports but the coalition Government sanctioned the zone off Southwold in 2012.

Shipping minister Mike Penning said it was a suitable area for carrying out ship-to-ship transfers based on the Maritime and Coastguard Agency’s and the industry’s experience of the successful use of these waters for transfer operations over a number of years without pollution of the seas and coasts.

Immediately after the new zone was agreed there was a noticeable drop in the number of tankers.

The reason for the current cluster is not known but oil prices are low and sometimes oil is stored at sea to wait for changes in prices on the world market.

Southwold Town Council has written to Government asking for the oil transfer site to be reconsidered and says “pollution is already occurring” .

The MCA, which is monitoring ship-to-ship transfer operations closely to ensure they meet safety standards, was not available to comment.