Italian PM Matteo Renzi revives plan for bridge from mainland Italy to Sicily

Controversial project thought to cost around €9 billion (£7.8bn) to build and faces heavy criticism

Italian prime minister Matteo Renzi wants to resurrect an idea proposed under Silvio Berlusconi (EPA)

A controversial idea of building a 3km (2 mile) bridge connecting the island of Sicily to the Italian mainland is being reconsidered by the country's prime minister, despite long-running concerns over costs.

Matteo Renzi said the roadway across the Strait of Messina would be economcially beneficial for both areas and create over 100,000 jobs for local workers.

Former prime minster Silvio Berlusconi pursued the idea in 2009 and estimated the cost to be €6.1 billion, but the porject faced significant opposition and was eventually abandonned four years later.

Experts now suggest the bridge would cost as much as €9 billion (£7.8bn) to complete, and have warned the high earthquake risk in the south of Italy could jeopardise construction work.

Italy is to hold a constitutional referendum on December 4 this year, and Mr Renzi was quoted as saying that "once the reforms are done, we can go back to planning our future", namely reviving "grand projects" including the Messina bridge.

Detailed plans for the bridge were first conceived in the early 1990s, but a succession of economic crises have ensured it has never become a reality.

Supporters claim the bridge would give boost Sicily's ailing economy and increase the tourist trade, but critics say the money would be far better spent improving the island's inefficient system of roads.

Concerns over the environmental impact of the bridge have also been raised, and many say it could potentially damage the scenery of the most southern point of Italy.

If realised, the bridge would become the world's longest suspension bridge by a considerable distance - exceeding the current longest, the Akashi Kaikyo Bridge in Japan, by 1.3km.