The board of directors of Stretto di Messina, the company formed to develop a suspension bridge between Sicily and the Italian mainland, has approved a design for the span, and the Italian government has said it wants work to begin this year.

Italian newspaper Il Post reports that work may begin as early as this year if the necessary approvals are given.

The plan has been under discussion since the 1960s, but it was not until 2005 that a contractor was chosen to build it. This was the Eurolink consortium led by Rome-based contractor Salini Impregilo – now known as Webuild.

At that time, it was estimated that the cost would be €3.9bn and the construction time was 5 years and 10 months. That estimate has now risen to €13,.5bn and the construction time to seven or eight years.

The Italian government’s approval was signalled by Matteo Salvini, the infrastructure minister, who said: “I confirm that the intention is to open the construction sites by 2024 and open the bridge to road and rail traffic in 2032.”

The project involves the construction of the longest single-span bridge in the world. It would have a total length of 3,660m and a suspended span of 3,300m. The two towers that support it would have to be 399m high.

The bridge would have to be able to resist winds of up to 128km/h, and would have to be stable in earthquakes.

It is thought that 4,300 workers would be employed on the project for seven years, with a peak of 7,000 reached in the busiest period. A clause has been included in the final project which provides for the cancellation of the works and the launch of a new tender if the costs exceed forecasts by 50%.