Postcard from... Stuttgart

Stuttgart is renowned for being a quintessentially German city.

The famous car manufacturer Mercedes-Benz has its headquarters just outside what is Germany's sixth-largest provincial capital.

For years Stuttgart was also proud to have Manfred Rommel, the son of the Second World War German general nicknamed the "Desert Fox", as its governing mayor. Rommel junior was a leading member of Chancellor Angela Merkel's conservative Christian Democratic Union, which kept an iron and unbroken political hold on Stuttgart for almost 40 years.

But last weekend, a leading environmentalist politician called Fritz Kuhn became Stuttgart's first Green Party mayor after securing a spectacular victory in Sunday's mayoral election. His win comes only a year after the Christian Democrats were ousted by the Greens from government in pivotal elections in the state of Baden-Württemberg – of which Stuttgart is the capital – for the first time in 60 years.

The trend is deeply worrying for Ms Merkel: it shows that voters in what was once held to be one of Germany's most secure conservative strongholds, nowadays have no qualms about ditching political allegiances held for decades and voting for a left-of-centre party with a reputation for anti-nuclear protest and environmental protection.

Germany's Greens were founded on the back of the anti-nuclear protest movement in Baden-Württemberg in 1980. But they have long since come of age. As of last Sunday, they now rule supreme in Germany's south-west. Angela Merkel has certainly taken notice.