Europe’s third most visited capital after London and Paris, Berlin draws foreigners and Germans alike to take in the city’s rich and troubled history amidst a thriving cafe culture. Some 20 million nights were spent in hotel rooms last year alone.

City officials say they hope to rake in at least 20 million euros ($27m) with the new tax.

Wowereit said some of the money would flow back into tourism by funding renovations for museums and other cultural landmarks.

But German hotel and restaurant association Dehoga says the tax targets hotels unfairly, leaving others who profit from the city’s booming tourism industry like taxi drivers and museums unscathed.

“The project isn’t thought through at all,” said Thomas Lengfelder, Dehoga’s director for Berlin, adding that his group would do everything it can to try to reverse the decision.

Opponents of the tax will have a tough time convincing officials to change their minds, given the example of the city of Cologne, which saw a 17 percent surge in visitors so far this year despite a similar tax that boosted city revenues fourfold.

“The tax didn’t have any negative effect on the number of overnight stays in Cologne since the tax was implemented last year — in fact the number increased,” Josef-Rainer Frantzen, head of Cologne’s tax and treasury office, said.