Bridge between Portpatrick and Larne could cost £40 billion
The figure was published in a report by the British Port Association.
A report commissioned by the British Ports Association has found that the construction of a bridge or tunnel between Northern Ireland and Scotland could cost up to £40 billion pounds, double the amount which was previously being stated.
In the report expert engineers concluded that the scale of the project was unprecedented and costs would be unmanageble.
The key issues facing the construction of the link proposed by the British Government are water depth (would have to cross the Irish Sea), the length of the stretch of water, dumped munitions and ordinance and complex geology.
The report also raised concerns over Brexit, stating that there are no natural places for border checks of goods, meaning increased waiting and journey time.
The British Ports Association believe the economic benefits of establishing a comprehensive port connectivity plan could bring in a 400% return on investment derived through cost savings for businesses, with a positive impact on emissions and the net-zero agenda.
Richard Ballantyne is the chief executive of the association, he said: "Whether it's value for money, we would say no.
"You'd be far better off spending money evenly around the country to link up coastal regions, strategic gateways, in our case, ports and harbours.
"It's an incredibly deep area of sea and that would only add to the costs and escalate the complexity of the project.
"Potentially this scheme could go on and on and on for many years and that is not something we want to see.
"We want to see a good return on investment at our strategic gateways and we want to see that as soon as possible."
An official feasibility study into the link has also been commissioned by the UK Government.
We have approached the UK Government for comment.