Finland and Estonia promise to look into potential €13bn rail link that would reduce journey time from two hours to 30 minutes

Drifting apart since the first Bronze Age fortifications were built, the Baltic Finns populating opposite sides of the Gulf of Finland were for centuries separated by empire, ideology and cold sea. Now, the historic brethren of present-day Estonia and Finland could be directly linked, as plans accelerate for a 50-mile tunnel running between their capital cities.

Although Helsinki can be glimpsed on a clear day from the top of Tallinn’s tallest tower, the only way across the gulf, bar a 500-mile drive also taking in Russia, is a two-hour boat trip. About eight million ferry journeys are made each year: a popular booze cruise for Finns, but also a weekly commute for tens of thousands of Estonians working in Helsinki. The tunnel would house a railway to bring them just a half-hour train ride away.

The cities’ leaders believe better links could greatly enhance the fortunes of both countries. On Tuesday, Estonian and Finnish ministers signed a memorandum of understanding promising to improve connections, including investigating further the idea of a tunnel to bolster the economic area formed by Helsinki and Tallinn’s more than 1 million people.

The two cities’ mayors have been pushing the idea for some years, since Estonia joined Finland in the European Union in 2004. The dream has been given added impetus by a recent preliminary study which suggested that the fixed link could be built for between €9bn and €13bn (£6.6bn-£9.5bn), would treble travel and boost trade between the cities in its first decade, and see 25m journeys by 2040.

The undersea tunnel is made particularly attractive because of a planned €3.6bn Rail Baltica high-speed train line, which will run from Tallinn to Poland and link into western Europe’s rail networks – and could also potentially connect Helsinki directly via train to Berlin and beyond.

The cities are, however, banking on Brussels paying several billion euros towards the scheme, and have applied for EU funding to carry out full feasibility studies.

Hannes Virkus, an adviser at the Estonian ministry of economic affairs, said: “The idea is really good and interesting and worth studying. But if we get the money, it’s going to take at least two years for the analysis to be completed, so only some time in 2018 can we can expect some real decisions on whether the tunnel will be built. It’s still some way away.”

However, there is real, equal enthusiasm from both sides of the Gulf of Finland. “The idea has been around for years, but we’re more optimistic now that it is going to happen,” he said.

The Channel Tunnel at 20: From the archive, 6 May 1994 Read more

As the major case study for the proposed link, the Channel tunnel linking Britain and France has been a source of inspiration and misgiving for the Baltic planners. While it demonstrates the engineering possibilities and was “a pointer towards a European future without borders”, the planners said it had not fulfilled its socio-economic potential, had a marginal impact on the integration of the regions around it, and perhaps most alarmingly, “showed that underestimating investment costs by 50% or more can be a real possibility”. “The Channel still represents a significant physical and cultural and psychological barrier,” the study noted.

Should the project go ahead, a Tallinn-Helsinki tunnel could be a reality by 2030. Traditionalists can rest assured that forecast demand means ferries would continue to run, and most cargo would still be transported across the water. Planners also expect the majority of tourist and leisure trips, where Finns regularly stock up on Estonia’s far cheaper alcohol, to be conducted by ship for many years to come.