On Friday it was revealed that the price of project had spiralled by 80 per cent to £80 million, and it would not be opened until 2018, four years after its first anticipated opening date.

Now Dundee City Council has revealed that the crucial task of engineering the foundations was threatened by the presence of an internationally important breeding population of harbour seals.

Ken Guild, leader of Dundee’s SNP administration, told The Times: “We expect to get the show on the road by March. There are cost implications of we don’t and there is also a problem with seal pups of all things.”

He said the project required the construction of a cofferdam, a temporary enclosed area built into the Tay estuary, which means some “fairly aggressive engineering where you put the dam into the bed of the river and also into rock”.

“This creates tremendous vibrations and low frequency sound, which carries for miles underwater,” he added.

The sound could disturb about 600 harbour seals which live around the mouths of the Tay and Eden estuaries.

They form one of only three colonies on the eastern coast of mainland Britain.

Pups are usually born in June and the animals are most vulnerable to disturbance during the breeding season.

Mr Guild said the council was holding “constructive talks” with Scottish Natural Heritage to try to find a solution.