Construction of the twin-bore tunnel between Bastad and Förslöv originally started as long ago as 1992 but was suspended in 1997 when the project was one-third complete because of serious environmental concerns. Tunnelling eventually resumed in 2005 and the final concrete segment was installed in September 2013.

Tracklaying has been carried out using a Plasser & Theurer SVM 1000 tracklaying train, which can lay up to 2km of track in 24 hours. Over the next few months installation of signalling, electrification, and telecommunications equipment will continue both inside the tunnel and on the approaches, with driver and rescue staff training scheduled to begin in the summer.

The tunnel is a key element in upgrading Sweden's West Coast Line between Gothenburg and Lund, replacing a steeply-graded single-track section on the line which is now 85% double-track. The tunnel will allow the number of trains to be increased from four to 24 per hour, while doubling the maximum permitted weight for freight trains. It will also allow the maximum speed of passenger trains to be increased from 80km/h to 200km/h.