An 18-kilometre long tunnel under the Baltic Sea was the preferred option to link Denmark and Germany, Danish politicians said Tuesday. "An immersed tunnel is something we have experience of," dpa cited Transport Minister Hans Christian Schmidt as saying after meeting with members of the transport committee. The two countries have for years discussed establishing fixed road- and rail link across the Fehmarn Belt, a strait between the Danish island of Lolland and the German island of Fehmarn. It is estimated that the link would cost 5.1 billion euros (7 billion dollars) and reduce travel times between Scandinavia and mainland Europe. The project is envisaged to be completed in 2020. A final decision on a tunnel or bridge link is pending.