After years of speculation, the idea of a bridge or tunnel between Northern Ireland and Scotland has been binned.
Prime Minister Boris Johnson previously talked up the prospect but a government report ruled it far too costly and challenging to construct.
And now the scale of spending on the feasibility study itself has emerged, prompting further criticism of the ill-fated proposal.
While some in Northern Ireland including the DUP have been supportive of the idea, others were sceptical from the outset and dismissed it as a "Tory vanity project".
Here is a brief overview of the long-running "Boris bridge" saga.
What was the idea?
The vision was to create a fixed link between Northern Ireland and Great Britain by constructing a bridge or tunnel to Scotland.
Two potential routes had been suggested - from Portpatrick to Larne, or near Campbeltown to the Antrim coast.
Consideration of the ambitious idea stretches back as far as the 1890s but nothing was ever built.
In more recent years the idea gained some political traction. In 2015 the DUP's election manifesto called for a feasibility study.
Prime Minister Boris Johnson also expressed enthusiasm for the idea.
Why has the proposal been scrapped?
The UK government commissioned a 'Union Connectivity Review', led by Network Rail chairman Sir Peter Hendy, which included assessing the feasibility of a bridge or tunnel between Northern Ireland and Scotland.
His report concluded that the project "would be impossible to justify" as "the benefits could not possibly outweigh the costs".
In addition to the huge expense, the inquiry also noted that the necessary work would be incredibly challenging.
The report described how 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.
The government accepted the conclusion of the report.
How much would it have cost?
The report found a bridge would cost £335 billion, while a tunnel would require a budget of around £209 billion.
These figures were well in excess of previous estimates, which for years suggested that a fixed link could cost between £15 billion and £20 billion.
How much did the study itself cost?
The UK government's Department for Transport (DfT) said the research into the feasibility of a fixed link cost £896,681.
The research was carried out alongside the wider review of connectivity in the UK, which cost £1,102,525.
DfT said the total of £1,999,206 for both studies was the amount spent on consultancy fees and department staff costs.
Sir Peter led the review alongside his role at Network Rail, and did not receive additional pay.
What have politicians said about it?
The DUP has previously expressed support for the bridge or tunnel idea, with its MP Sammy Wilson saying that Mr Johnson could "win back the trust" of unionists by building the fixed link.
SDLP Infrastructure Minister Nichola Mallon dismissed the idea as a "Tory vanity project" and said the money would be better spent tackling existing issues in Northern Ireland.
Last year Mr Johnson's former chief adviser Dominic Cummings dismissed the idea as the "world's most stupid tunnel to Ireland" as he criticised the Prime Minister's priorities.
Louise Haigh, Labour's shadow transport secretary and former shadow Northern Ireland secretary, said the spending on the report showed the Conservative Party's "sheer disrespect for public money".
SNP MP Mhairi Black said the bridge was an "unworkable, doomed from the get-go idea" that demonstrated the Tories' "warped spending priorities".
In the Irish government, Tánaiste Leo Varadkar some years ago said the bridge idea was "worth examining".
What did the UK government say ?
DfT said the purpose of the Union Connectivity Review was to examine all aspects of transport links between the UK nations to "boost and deliver further opportunities for people, families and communities".
It added: "As part of this detailed review, we consulted with the best engineers and technical consultants and undertook extensive social and geographical research to carry out a comprehensive study.
"This has informed our approach to rail, road and air, including making travel cheaper for all parts of the UK by reducing Air Passenger Duty by 50% for domestic flights."
