The facility would be accompanied by a new light rail “metro” system for the city, while Central station would be extended across the Clyde to accommodate HS2 trains.
The £10 billion scheme could be funded in part by Scotland’s share of UK spending on the high-speed line under the Barnett formula.
The new metro network would include a line between the city centre and Glasgow airport, using the route of the segregated Fastlink busway rather than on the main rail line to Paisley, as previously planned.
The proposals have been devised by the Glasgow Connectivity Commission, which was launched by the city council to improve transport.
The cross-city tunnel, similar to recent ones in cities such as Stockholm and Munich, would enable through trains between the north and south of Glasgow for the first time, such as between Edinburgh and Ayrshire. It would run from the Paisley line in Pollokshields on the south side to Cowlairs, beyond Queen Street, on the main line north.
The new station would have escalators at each end of its platforms, providing access to Central to the south and Queen Street to the north.
The commission, chaired by transport expert Professor David Begg, said the metro should serve areas of the city without railways, which had suffered economically as a result.
It said the network should start by linking Glasgow airport with Paisley Gilmour Street station before continuing east to Glasgow city centre via Renfrew, Braehead and the Queen Elizabeth University Hospital. The trains would carry more passengers than existing rail carriages and accelerate faster to provide a rapid transit service.
Other metro routes could use former rail lines, such as under the Botanic Gardens in the west end, and run on streets such as Edinburgh Road in the east end.
Prof Begg said the report’s recommendations were “bold, ambitious and transformative, but we are also confident they are achievable” – as they had undergone detailed study in the past. He said the tunnel had been considered over the past 30 years and found to be viable. However, cheaper options such as the expansion of Queen Street station had been chosen instead.
City council leader Susan Aitken said: “These proposals are worthy of detailed consideration. This is the kind of thinking which Glasgow has needed.”
Transport secretary Michael Matheson said the plans would be considered as part of a Scotland-wide strategic transport projects review.
Glasgow Airport managing director Mark Johnston said: “It is widely accepted the airport needs to be connected to the rail network and the commission has reinforced this position.
“Its ambition for a city-wide metro system starting at the airport is forward thinking and could address some of the major transport issues facing the city region.”
The metro could be created from parts of the existing heavy rail network, re-opened sections of dormant infrastructure, wholly new sections of route and on-street tram running, it is proposed.
This first leg should be completed by 2025 and the importance of the corridor means “it is no longer appropriate to conceive a rail link to the airport as a freestanding project”, the report noted.
The commission was established in November 2017, with its first report published last year exploring how the local authority could transform the city centre and reverse a steep decline in bus use.
Its second report has now looked at matters outwith the council’s control, namely the road and rail network. The findings state Glasgow has a good transport network by UK standards, but that it falls “substantially short” compared to some European cities.
The commission found the separation of the city’s two main railway stations was one of the main barriers to connectivity in the area. Twenty trains would run between the two stations an hour under proposals for a new underground rail link.
Other key recommendations in the report included developing plans for bus priority on Glasgow’s motorway network and preparing for the shift to electric and autonomous vehicles by considering new methods of road charging.