BORIS Johnson’s plan for a fixed link between Scotland and Northern Ireland has been exposed as an impossibly expensive fantasy by an official study into the idea.

Despite initial estimates that a tunnel or bridge could cost £20billion, experts said the final cost could be more than £300bn and it could take 30 years to build.

The HS2 rail project is estimated to cost £100bn.

Sir Peter Hendy was commissioned by the UK Government to assess the feasibility of constructing a fixed transport link between Northern Ireland and Great Britain as part of his union connectivity review.

But the official study has concluded that to construct either a tunnel or a bridge between the two countries would be “impossible to justify” due to the extortionate costs involved.

The research found a bridge or tunnel would be the longest structure of their kind ever built.

In his forward, Sir Peter said: “The indicative cost estimate for the full route, including optimism bias, is £335bn for a bridge crossing and £209bn for a tunnel crossing.

“The bridge or tunnel, and the associated very significant works on either side for a railway and possibly for roads would take a very long time.

“Planning, design, parliamentary and legal processes, and construction would take nearly 30 years before the crossing could become operational, even given a smooth passage of funding and authority to proceed.”

Sir Peter said that “future transport technological advances” including autonomous vehicles could mean a link could be brought forward “at a lower cost”.

But he added: “For now, though, the benefits could not possibly outweigh the costs to the public purse. “It is therefore my recommendation to Government that further work on the fixed link should not progress beyond this feasibility study.”

SNP transport spokesperson, Gavin Newlands, said: “From the outset, Boris Johnson’s plans for a bridge between Scotland and Northern Ireland were fantasy – and this report shows that the £20 billion figure the UK government said it would cost was a fantasy too.

“The whole project lays bare the incompetence of the UK government and how out of touch with Scotland it is."
He added: “However, the £20 billion the bridge was originally reported to cost and which his government did not dispute when he was touting it – over £3,600 per person in Scotland - should be handed over to the Scottish Government to be used to meet Scotland’s priorities and transport needs.
“At the very least, that money should all be invested in projects that deliver a tangible benefit for Scotland, like cross border high speed rail.”

The report also said Beaufort’s Dyke – an underwater trench on the most direct route between Scotland and Northern Ireland – would need to be “carefully surveyed” due to a million tons of unexploded munitions being dumped there between the First World War and the 1970s.

A bridge would have a “sacrificial outer layer” enabling its main structure to survive a “local detonation”, the study said.

In September, the Prime Minister was forced to admit his plan for the link was not going to proceed as he downgraded the idea to a mere “ambition” and put other major projects including high-speed rail ahead of his vision for the 30km link.

The PM had boasted about the idea since coming to power in 2019 and the feasibility study into the link was ordered in March.

Initially, a proposed tunnel from Portpatrick in Dumfries & Galloway to Larne in County Antrim, dubbed the ‘Boris burrow’, was estimated to cost £15bn to £20bn.

Both the Scottish and Northern Ireland governments questioned whether the money would be far better spent on something else.

Sir Peter has also carried out a wider investigtaion into transport for the UK Government and has published the union connectivity report.

In Scotland, Sir Peter recommended reducing journey times and increasing capacity on the West Coast Main Line as well as routes between Scotland and London, and conducting an assessment of the east coast road and rail corridor.

The review has warned that devolution “has sometimes resulted in strategic cross-border transport schemes being less of a priority than those schemes which are wholly contained within a single nation”. 

The study pointed to an ambition to cut rail journey times between Scotland and London to three hours to “generate considerable transport user benefits and revenues” - while Sir Peter recommended work to “increase rail capacity” by upgrading the West Coast Main Line north of Crewe, as well as “reviewing options for alternative northerly connections between HS2 and the West Coast Main Line”. 

Sir Peter also warned that “there has been no attempt to develop a business case for an upgrade to the A1 which considers the cost and benefits of doing so along the full extent of the route between Newcastle and Edinburgh”.  

He added that no work had been carried out on an east coast “cross-border study”. 

Sir Peter recommended that “the UK Government should seek to work with the Scottish Government to develop an assessment of the east coast road and rail transport corridor from north east England to south east Scotland, including improvements on the East Coast Main Line and the A1.”

Upgrades to the A75 in the south of Scotland were also recommended, which would improve connectivity to Northern Ireland, while calls were made for improving the A55, M53 and M56 and the South Wales Corridor in Wales, along with the North Wales Coast Main Line and rail links to the Midlands from Cardiff.

With transport a devolved policy area, SNP Finance and Economy Secretary Kate Forbes has called for an assurance that the Scottish Government budget will not be raided to pay for the projects.

“We always seem to be invited in when it comes to rubberstamping UK Government plans, and my concerns are twofold,” she said on BBC Radio Scotland’s Good Morning Scotland programme.

“Firstly, is this additional money?

“In other words, they talk about adding to Scotland’s infrastructure – is it really additional or are they just netting it off our capital budget?

“Because historically, what the UK Government has done is given Scotland funding and then we determine priorities in consultation with local authorities and communities."

She added: “And the second point is, are these Scotland’s priorities?

“We saw the Prime Minister quite recently ditch the ridiculous idea for a bridge to Northern Ireland.

“Are we going to have sensible ideas coming from this?”

A Scottish Government spokesman said: “Transport is devolved to Holyrood and the UK Government should respect that.

“We will always seek to engage constructively with the UK Government – for example, on cross-border rail and our shared desire for HS2 to serve Scotland – but UK ministers have no role in deciding investment in Scotland’s trunk roads.

“Scottish ministers have not been sighted on the recommendations of the union connectivity report, however if UK ministers really want to play a helpful role, then they could simply deliver the funding we need for such infrastructure investment in line with established budgetary mechanisms for Scotland to determine our spending priorities.”