BERLIN (NYTIMES) - A German court on Friday (March 5) suspended the right of the country's domestic intelligence agency to conduct surveillance of the Alternative for Germany (AfD), the leading opposition in Parliament, pending the outcome of a legal challenge by the far-right party.

The ruling, made by the Administrative Court of Cologne, came two days after news leaked to the media that the intelligence service had decided to investigate the party, known by its German initials AfD, on suspicion of being a threat to democracy, based on its anti-Semitic, anti-Muslim expressions and members who have been dismissive of Germany's crimes under the Nazis.

The move to classify the group as extremist and in need of observation by the intelligence services serves as a strong example of the lengths that a Western democracy is willing to go to defend its system against the threat of right-wing forces that have gained in popularity in the United States and Europe.

But the court ruling Friday underscored a particular quandary in Germany between the need to protect against threats to the state while safeguarding civil liberties. Because of its Nazi past, Germany has both aggressive measures to fortify the Constitution as well as tough protections for its citizens against state intrusion.

The legal challenges filed by the AfD against its surveillance is testing that balance.

Although the intelligence office, the Federal Office for the Protection of the Constitution, known by its German initials BfV, had declined to comment on the leak Wednesday, the court found that it violated a confidentiality agreement and jeopardised the party's guarantee to equal opportunity.

In its ruling, the court revoked the intelligence agency's right to take further action against the party or to publicly discuss its consideration of taking action against the party until a final ruling is handed down in a lawsuit the party has filed to prevent the government from classifying it, or its members, as extremist.

The court stressed that Friday's decision would not influence the outcome of the AfD lawsuit, which is still being considered. It is not clear when a ruling may come.

The party celebrated the ruling, which came as a blow to the recently revamped intelligence service, which has focused more of its attention on clamping down on far-right extremism after its former chief was ousted in 2018 over comments seen as sympathetic to the far-right.

"This decision is not only a great victory for us but also for the rule of law, because the Administrative Court has shown that the illegal action of the Office for the Protection of the Constitution against the largest opposition party can be stopped by legal means," the party's leader, Mr Jorg Meuthen, said.

For years Germany saw itself as immune to the nationalist movements driven by far-right rhetoric that disrupted the democracies in Hungary and Poland by weakening the judiciary and the independence of the press.

Watching the rise of Mr Donald Trump in the US presidential race of 2016, many believed their country had been hardened to the lure of unvarnished nationalism and anti-establishment sentiment by the lessons of World War II.

But since winning 12.6 per cent support in 2021, the AfD party has brought its anti-establishment stance, denigration of the press and casting Muslim immigrants as criminals to the floor of the German Parliament, where it has served as the largest opposition party.

During that time, the country has also seen a rise in far-right crime, including the killing of a regional politician on his front porch near the central city of Kassel, an attack on a synagogue in the eastern city of Halle and fatal shooting of nine people of immigrant descent in the western city of Hanau.

Increasingly concerned about the party's positions, the domestic intelligence agency has spent two years scrutinising the speeches and social media posts of AfD officials for evidence of extremism, including the demeaning of foreigners, questioning of the democratic system and dismissal of the crimes of the Nazis.

An assessment amounting to some 1,100 pages concluded that the party's position violated key principles of liberal democracy, not least Article 1 of the German Constitution, which states that human dignity is unassailable, officials said.

As part of its anti-establishment stance, AfD has also cast itself as the victim of political intrigue, fuelled by incidents such as the leak to the press Wednesday, said Dr Axel Salheiser, who teaches at the Institute for Democracy and Civil Society at the University of Jena.

"This is proof that the checks and balances are functioning," Dr Salheiser said. "That is the paradox; they are always positioning the far-right fringe as a result of the system not functioning, but they are always quick to go before the courts, often successfully."

The outcome of the final ruling could have an impact on how the AfD is viewed as German political parties begin gearing up for a general election Sept 26. That vote could see a reshuffling of the government after 16 years under the leadership of Chancellor Angela Merkel, who is not running again.

In January, and again last month, the court ruled in favour of the intelligence service, allowing it to proceed with investigating members of the AfD on suspicion of extremism. But in an effort to prevent the party from being branded as extremist while the court continues to weigh the original challenge, it added the stipulation that the status could not be made public.

After the information about the agency's plan to place the whole party under surveillance was made public, even though the agency did not discuss it, the court saw the situation as having changed. As a result, it overruled its own decisions from earlier this year.

The court said in a statement that it was prohibiting "the Federal Office for Protection of the Constitution from classifying or treating the party as a 'suspicious case' and from any further announcements of such a classification or treatment as a 'suspicious case' until a decision is made on the emergency suit filed by the AfD."