Berlin is one of a handful of cities whose branding campaign has worked. The German capital struggles with mass unemployment, and more than a third of the city’s residents are claiming benefits – yet the city has successfully managed to market itself as the cultural centre of Europe.

Artists, musicians and writers are flocking there in droves, attracted by cheap housing and an affordable alternative lifestyle. Over the last decade, tourism in Berlin has doubled, reinvigorating a city teetering on the edge of bankruptcy.

But the man responsible for Berlin’s new image, and who coined the phrase “poor but sexy” to describe it, is stepping down: last week, in an unexpected announcement, Klaus Wowereit, the mayor for nearly 14 years, announced he would retire before the year was out.

“Wowi”, as his supporters affectionately refer to him, came to power in 2001, when the city was still reeling from the scars of the Cold War. Since then, the openly gay Social Democrat has been lauded as an emblem of the liberal capital’s tolerant values. He’s also championed Berlin’s identity as a hub of creative talent, describing the city as “Europe’s most exciting start-up capital”.

The combination of cheap rents and a welcoming attitude to unconventional outsiders has allowed a torrent of innovative new companies to flourish in the city, fuelling an economic boom unseen in the region for years. Creative industries now account for a fifth of Berlin’s GDP; this figure will only rise as immigration to the capital continues. In such a massively underpopulated city, it’s hard to see this trend reversing.

Yet despite all these achievements, Wowereit’s popularity tumbled due to the monumental catastrophe of its new airport, Berlin Brandenburg Willy Brandt. Heralded as one of the capital’s most ambitious-ever construction projects, Willy Brandt was originally intended to deal with Berlin’s growing numbers of visitors by replacing three smaller airports, Schönefeld, Tegel and Templehof. (The last of these was closed in 2008, and is now a public park).

Berlin’s airports, past and future. The new Brandenberg/Willy Brandt will be adjacent to Schönfeld. Image: BajanZindy/Skew-T, via Wikimedia Commons.

The new facility was meant to open in 2010, but a combination of poor management and corruption allegations have pushed opening day back until 2016 at the earliest. The cost of the project is running billions of euros over budget, too.

And, as chairman of the supervisory board, Wowereit has seen the blame for the failings placed squarely at his feet. After the airport’s fourth postponement early last year, almost every major newspaper in Germany was calling for his resignation, with massively-popular tabloid Das Bild writing:

“It’s a cheap trick! A farce! A complete piss-take… Germany’s engineering prowess has been dragged through the mud.”

To outsiders this may seem like an over-reaction (just compare it to London mayor Boris Johnson’s attempts to force an unwanted new island airport on his city); but there’s more at stake here than Germany’s reputation for punctual efficiency. To many Berliners, the affair encapsulates Wowi’s tendency to emphasise style over substance. That, in turn, has raised further questions over the efficacy of Berlin’s economic makeover.

There is after all, a downside, to the city’s cultural boom. It’s gentrified many inner city areas, but the resulting increase in rents has driven out the creative talent that underpinned Berlin’s reputation in the first place. Many locals are wondering if it’s all just a bubble.

What Klaus Wowereit’s legacy will be remains to be seen: matters are now out of his hands. If his replacement can salvage the airport in time, the once-loved mayor might be remembered for his grand vision of transforming Berlin. More likely, though, the project will drag on for many more expensive and unsuccessful years, permanently fixing his reputation as the showman who failed to deliver on his promises.

Wowereit has set his end-date as 11 December. Perversely, and in a classic display of German Schadenfreude, many critics are actually hoping he stays on a bit longer – fulfilling his reputation as the mayor who kept on delaying.