The project, nicknamed the ‘Boris Burrow’, could be given the green light in the next few weeks, with a proposal paper set to be put to the PM. But the SNP’s Northern Ireland spokesperson Richard Thomson has slammed the plans.
Mr Thomson said: “The UK Government toys with another headline-grabbing distraction but, in reality, a fixed link between Scotland and Northern Ireland will only serve to highly the competitive disadvantage that Scotland faces thanks to Boris Johnson’s damaging Brexit deal.
“Boris Johnson couldn’t even build a 366-metre bridge across the Thames when he was London Mayor – but thinks we’re going to trust him to deliver one of the most complicated infrastructure projects imaginable.”
Stormont’s Minister for Infrastructure, Nicola Mallon, also dismissed the idea as “nonsense”.
And Tory MP Simon Hoare, chair of the Northern Ireland Affairs Select Committee, also mocked the project.
He tweeted: “The trains could be pulled by an inexhaustible herd of unicorns overseen by stern, officious dodos.
“A PushmePullYou could be the senior guard and Puff the Magic Dragon the inspector.
“Let’s concentrate on making the Protocol work and put the hallucinogenics down.”
The multi-billion infrastructure project, which has been backed by Scotland Secretary Alister Jack, could be greenlit within weeks.
READ MORE: EU still paying price for ‘rash mistakes’ made at Maastricht
The tunnel would carry cars and lorries as well as rail passengers.
Jim Steer, of the High Speed Rail Group, said: “It sounds crazy now, but before the Channel Tunnel was built there was a similar debate.”
The 366-metre bridge would cost between £8billion and £10billion, according to architect Alan Dunlop.
Civil engineer Eoin Neylon added: “He’s [Boris] going to run into very, very similar stumbling blocks when it comes to trying to go underground.
“If he is spending this kind of money, a tunnel would at least get away from the severe weather issues that would keep a bridge closed for up to 100 days of the year.
“However, I still don’t think it’s going to be coming in with a price tag of anything approaching acceptability to the British taxpayer.
“You’d do an awful lot more for the people of the six counties with 20 billion than you would by giving them a tunnel…
“God knows how feasible the actual operation of that as a proper trade route would even be.”