A socialist has become a state governor in Germany for the first time since the collapse of the GDR in 1990, leading a coalition in an eastern state and prompting a significant shift in the national political landscape.

Bodo Ramelow, 58, a former trade unionist, was voted into office in a second-round ballot in Thuringia to applause from the parliament in the city of Erfurt. Ramelow is a moderate member of Die Linke (the Left), which has its roots in the socialist party that ruled East Germany and makes no secret of its anti-Nato and pro-Russia stance. Ramelow will head a coalition of Die Linke, the Green party and the centre-left Social Democrats (SPD), bringing to an end 24 years of conservative rule in the state. Dubbed red-red-green – according to the colour-coding of German parties – the coalition government is seen as something of an experiment that could provide a workable model for a national government when federal elections take place in just under three years. Die Linke has considerable support in the former east and had already been elected as a junior partner in various coalitions in the region. However, Ramelow’s election marks the first time it has led a government.

He takes power amid charges that his party has not distanced itself sufficiently from the former communist regime.

Never before in a fully democratic Germany has a regional election triggered so much protest, with tThousands of people protested against Ramelow’s election outside parliament in Erfurt on Thursday evening ahead of the vote, declaring that the “perpetrators” were heading back into office.

Demonstrators included former East German dissidents, some of whom had spent time behind bars for their opposition views. They shouted “Stasi out!” in reference to East Germany’s repressive secret police, and “the Social Democrats have betrayed us”.