The tunnel would be 38 kilometres long and would be the first land link between the continents of Europe and Africa.
Just over 27 kilometres would be submerged below water, while the rest would be above it The maximum depth would be 475 metres below sea level.
Rafael García-Monge Fernández, president of the Spanish Society of Studies for Fixed Communication through the Strait of Gibraltar SA (SECEGSA), told a recent conference in Algeciras – in the Bay of Gibraltar – that the project is back on, reports Spanish regional daily Diario de Cadiz.
Previous feasibility studies had cast doubts on the project but a new assessment by the University of Zurich and Herrenknecht, the world's largest tunnel construction company, argues that the project is feasible. The next step would be to build a tailor-made prototype tunnel borer, estimated to cost €32 million.
Both Morocco and Spain are apparently keen to pursue the project, although the European Union would have to provide substantial funding. One of the difficulties would be maintaining the right gradient to meet international requirements for high speed transfers.
The tunnel could be used to transfer solar energy from the Sahara to Europe, adds the report. Initial estimates suggest the project could cost €8 billion.
According to SECEGSA's website, high speed trains operating in the tunnel could make cargo journeys between Madrid and Marrakech or Casablanca up to three times shorter.