2007 An interim agreement was reached in
Berlin between the Danish and German authorities on 29 June (represented by their transport ministers) to proceed with the construction of the fixed link. Details provided by
Danmarks Radio stated that the Fehmarn Belt Fixed Link would run from a point about east of
Rødby in Denmark to
Puttgarden on the Island of Fehmarn, which was already connected by bridge to the German mainland. Construction would start in 2015 and was expected to be completed by the end of 2021.
2009 On 26 March, the construction was ratified by the
Danish Parliament, and approved by the
German Parliament on 18 June.
2010 It was announced in December that a tunnel would be used rather than a bridge to present fewer construction risks than a cable-stayed bridge, which would be pushing the limits of the technology. The cost and the construction time would be roughly the same. However, national approval procedures in both countries needed to be completed. In Germany, that involved the application for a plan approval process. In Denmark, the project would require the passage in Parliament of a Construction Act. On 16 December, the German government announced that it was postponing development of the railway link to the Fehmarn Tunnel until after 2015. According to a report in
Der Nordschleswiger, German Traffic Minister
Peter Ramsauer decided to reduce planned government investment in new infrastructure in Germany by 25 per cent because of the
economic crisis. It was not immediately clear what effect the postponement would have on the overall Fehmarn Belt Fixed Link project.
2013 In October 2013, the tunnel company applied to German authorities for approval according to environmental law and other laws of Germany and EU. This was rejected in 2015 because new legislation that appeared in the meantime was not accounted for.
2015 On 25 February, the bill for the Construction Act for the Fehmarn belt link was introduced in the Danish Parliament.
2016 On 13 June, the tunnel company applied again to German authorities for approval, based on an updated application of 11,000 pages adopted to new legal principles that appeared since last application.
2018 On 28 December, the German authority decided to approve the project.
2019 On 6 February, Femern A/S received German plan approval for the tunnel. This had been appealed to the
Federal Administrative Court by political objectors.
DB Netz AG submitted a document to the
BMVI detailing variants of the rail connection to the tunnel later that same month. The railway plans would need approval by the German Parliament. In March, Femern A/S decided on a Government request to start large preparatory work on land, such as building a factory for concrete tunnel elements, in anticipation of a positive German court decision later.
2020 On 3 March, the German Federal Ministry of Transport, the State of Schleswig-Holstein and Deutsche Bahn announced that a new 1.7 km long immersed
Fehmarn Sound Tunnel (German:
Fehmarnsundtunnel) with four road lanes and two rail tracks, costing approximately €714 million, is scheduled to be built by 2028, and the current
Fehmarn Sound Bridge, which was at risk of becoming a bottleneck, would be preserved for pedestrians, cyclists and slow road traffic. On 3 November, the
Federal Administrative Court ruled that the project could be built, but some reefs would have to be considered. The
Naturschutzbund Deutschland described it as a "dark day for the marine environment".
Sabine Leidig (Die Linke) commented: "The ecological effects and the burden upon the neighbours of this giant project are much too large, compared to its small utility."
2021 On 1 January, work began on the actual tunnel construction, with an official online ceremony.
2022 On 18 January, the German
Federal Administrative Court in
Leipzig imposed a construction freeze on the areas near protected
reefs, while it considered legal challenges from a group opposed to the project. On 12 May, work began on the tunnel's northern entrance (Danish side). On 24 May, the dredging work of the tunnel was 50% completed, i.e., 11 km had been dredged. Due to inflation and interest rates, it was reported that in the first nine months of 2022 construction costs had risen to about 15.5 million krone per day. On 14 December, all complaints from political organisations were dismissed by the
Federal Administrative Court in
Leipzig.
2023 On 6 January, the dredging work for the tunnel was 70% completed. In July, the German work harbor became operational and in August the tunnel element factory was completed. In December, the first tunnel element was finished and it was expected to be immersed in the Fehmarnbelt in 2024.
2024 On 15 April, construction work on the railway link from Puttgarden to Lübeck started on Fehmarn. Some of the sections of the German railway project, mainly south of
Altenkrempe, were then still being planned again as they had been dismissed by authorities.
2025 The first tunnel element has been installed and tunnel construction continues, starting from the north end on the coast of
Lolland, with each individual element weighing 73,000 tonnes being cast on site, towed into position and carefully sunk into position to link onto the end of the lengthening tunnel. A viewing platform with a height of 24 m opened in Rødbyhavn at the beginning of 2025. However, challenges appeared in 2024 and 2025. The specially designed vessel, which shall install the tunnel elements into the water, and its work methods have not been approved by German environmental authorities. These strengthened requirements compared to when the vessel was designed, including underwater noise and mud spill, and more. It is, as of the end of 2025, a 1½-year delay in approval, and the vessel's approval is uncertain, and environmental authorities can invent new requirements when existing ones have been fulfilled. It is clear at this time that the tunnel will not be finished in 2029. ==Criticism==