The party, now running second in the polls and casting itself as anti-establishment, has 22 cases pending before the German Constitutional Court that were brought collectively by its 78 federal lawmakers, including nine filed in the past year.

They include claims that range from seeking the right to chair political committees to contesting occasions when the parliament speaker called the party to order in the Bundestag.

An AfD spokesperson said the filings are based on "principled matters of law" and pointed to three rulings in 2022, 2020 and 2018 in which courts had ruled that the government had infringed on the party's rights.

"In all these cases the Constitutional Court found that the state - concrete ministers, the Chancellor, and the government itself - had violated the AfD's rights," the spokesperson said.

Some lawyers and political opponents say some of the cases are designed to snarl the court system as part of a political strategy to make the German state less effective.

"It's designed to sow dysfunction that the anti-system parties can claim only they can fix," said Alex Clarkson, a politics professor at Kings College London.

While other opposition political parties also turn to the Constitutional Court with allegations of rights infringements, the AfD - which stands for Alternative for Germany - is doing so with more frequency.

The 197-member-strong conservative group in parliament filed five complaints last year, and the ex-communist Left party, which espouses anti-system views like the AfD, brought two.

Cases involving lawmaker rights must be heard by the full Constitutional Court, and the relevant trial chamber held such hearings only five times last year. At that rate the pending cases filed by the AfD, which account for half the 18 legislator rights cases brought to the court last year, would take more than four years to be heard.

Some of the cases could be rejected as abusive or unjustified, but only after a hearing.

The Constitutional Court declined to comment on the number of AfD cases.

'ABUSE OF LAW'?

Some complaints filed by the AfD touch on occasions where Chancellor Olaf Scholz and other ministers in his coalition cabinet spoke negatively about the anti-immigration, anti-European Union party.

Though Scholz and his Social Democrats hold the view that the AfD is a racist threat to German democracy, the AfD said these specific remarks breached an obligation to neutrality.

The heavy burden on the Constitutional Court comes at a time when Scholz's three-party coalition is considering constitutional amendments to shore up the independence of the court, based in Karlsruhe near the French border.

With the AfD now topping the polls in formerly communist eastern German states where regional votes are due later this year, many in the political mainstream are mindful of moves made by right-wing populist governments in Hungary and Poland over the past decade to clip the wings of top courts.

During court hearings the AfD has also been accused of trying to drag out proceedings.

At a hearing before another court in Muenster last week, where the AfD was challenging security services' right to tap its calls and recruit informants in its ranks, it was accused of "delaying tactics" by the lawyer for the security services.

The party filed two motions to postpone the trial and two applications for judges to be dismissed for alleged bias.

The presiding judge, Gerald Buck, described the motions to dismiss his chamber for bias as "abuse of law".

The volume of questions sent by AfD legislators to ministries is also far higher than those of other parties.

Since the start of this legislative term in September 2021, the party's lawmakers have asked 1,439 questions of ministries, twice as many as the conservatives' 197 members.

Questions included asking the government how much it was spending on promoting gender awareness in China (the answer: nothing, though it did fund some NGOs for whom that was a priority). In February, the party's leaders asked whether anti-AfD protesters were far-left extremists.

Since such questions must be answered according to strict deadlines, officials from several ministries have said the burden has grown greatly.

None were willing to discuss the matter, however, because of another suit at the Constitutional Court in which the AfD is demanding ministries be forced to behave with "neutrality" toward the party.

That leads some activists to worry about the consequences if, as seems possible, the AfD becomes the largest party in a federal state in elections later this year.

Max Steinbeis, a rule-of-law activist, founded the Thuringia Project, an initiative to safeguard democratic structures in the eastern state in the event that the AfD wins.

The AfD "is using legal means and minority rights to make more credible its narrative that democracy, in its current form and without the AfD in government, doesn't work," he said.

(Additional reporting by Andreas Rinke; writing by Thomas Escritt; editing by Mark Heinrich)

By Ursula Knapp and Thomas Escritt