Voters have backed a £3.8 billion plan to convert Stuttgart’s main rail terminus into an underground through high-speed station.

Controversy over the scheme helped the Greens and Social Democrats push Chancellor Angela Merkel's Christian Democratic Union out of power in the state of Baden-Wurttemberg in March 2011.

Construction work on the new station was halted after violent protests but when the rail plan was put to a referendum in November 2011, it was backed by 59% of the people.

State premier Winfried Kretschmann of the Green party said: "I am a bit surprised by the result. It is a hard decision.

"But it is a good day for democracy that so many people took part in the referendum. We want to use this form of consulting the public more often in the future."

Deutsche Bahn will rebuild the station on the same site 12 metres below ground, with four through platforms that will avoid the need for trains to reverse at Stuttgart.

Most of the 1920s built main building and its 12-storey tower with its Mercedes-Benz star on top will be retained in the Stuttgart 21 plan. The project may niw not be completed until 2020.