Meet Sebastian Münzenmaier. He is a member of Germany’s far-right Alternative for Germany (AfD) party that won 13% of the vote in last month’s German elections. He is also a convicted football hooligan.

Three weeks ago, Münzenmaier was handed a six-month suspended sentence for his role in a vicious attack on rival football fans in 2012. He called the verdict “outrageous” and vowed to appeal.

As reported by The Financial Times, Münzenmaier and the other 91 AfD MPs worry much of Germany’s political class.

“The tone of the debates will become much more raucous,” says Alexander Hensel, a researcher at the Göttingen Institute for Democracy Research. “The [AfD] uses concepts that are, for good reason, banned in German political culture: it seeks attention by deliberately breaking through the political consensus.”

The AfD dismisses fears it will subvert Germany’s democratic rules. It says it will inject new vigour into a parliament that, under Chancellor Angela Merkel, has become increasingly sleepy and irrelevant, reported The Financial Times.

“The Bundestag used to be a place where questions of principle were debated and argued over… [but] that’s all gone now,” says Alexander Gauland, AfD deputy leader.

Wolfgang Schäuble, the former finance minister who will be speaker of the new Bundestag, is expected to nip any AfD provocations in the bud.

Meanwhile, AfD’s candidate for deputy speaker of parliament, Albrecht Glaser, is notorious for his anti-Islamic rhetoric. He has said Muslims should be denied constitutional guarantees of religious freedom because Islam is a “political ideology” rather than a religion. The other parties have already said they will block his appointment.

AfD MPs frequently demand to know how much public money is being spent on refugees, whether they’ve committed any crimes, and whether any have become Islamist radicals. Other parties have accused AfD of wasting taxpayers’ money.