COPENHAGEN • Denmark will require anyone who takes Danish citizenship to shake hands at the naturalisation ceremony, under a law passed on Thursday, which lawmakers say is aimed at Muslims who refuse on religious grounds to touch members of the opposite sex.

The law has prompted strong reactions from some of the mayors who must conduct such ceremonies, and who are upset that they will become the faces and fists of a policy they call awkward, "purely symbolic" and irrelevant to an applicant's qualifications.

They say the Danish Parliament, which approved the measure, has artificially elevated a social custom to a national value.

But Denmark is not alone. The authorities in Switzerland and France have recently cited "lack of assimilation" in rejection of citizenship to foreigners who refuse to shake hands with officials.

"If you arrive in Denmark, where it's custom to shake hands when you greet, if you don't do it it's disrespectful," said Mr Martin Henriksen, a lawmaker who has been critical of Islam and is the right-wing Danish People's Party's spokesman on immigration. "If one can't do something that simple and straightforward, there's no reason to become a Danish citizen."

He said the law, which takes effect on Jan 1, was required because of "Muslim immigration to Denmark over a long time" and added that he hoped it would be followed by a ban on Muslim women wearing veils at citizenship ceremonies.

Integration Minister Inger Stojberg posted on Facebook that a handshake was a "visible sign that you've taken Denmark to heart".

Some Muslim and Jewish groups prohibit or discourage their faithful from touching members of the opposite sex outside their families.

The handshake requirement, which includes a provision that the wearing of gloves is unacceptable, is the latest in a series of Danish anti-immigrant measures that critics say are symbolically charged but serve little purpose.

The government recently announced plans to isolate certain migrants it wants to deport on a small, out-of-the-way island, and Parliament approved funding for the project on Thursday.

Earlier this year, the Parliament prohibited the wearing of face veils in public, although researchers say only about 200 Muslim women follow the practice in Denmark.

In 2015, the country sharply cut social programmes for asylum seekers, and a law passed in 2016 allows the authorities to confiscate migrants' valuables to help cover the cost of their stays in Denmark.

The handshake requirement will deter few applicants for citizenship, officials said, but it sends a harsh message to Muslims, and many mayors who conduct citizenship ceremonies said they would find ways to avoid it.

"It's against my ideology and conviction to have to force other people to have body contact," said Mr Thomas Andresen, the Mayor of Aabenraa which is near the border with Germany.

Mr Andresen said he could either arrange to have local officials of both genders take part in the ceremonies or have state officials take over. Either way, he would look for pragmatic solutions while protesting against laws "gone too far".

Mr Mogens Jespersen, the Mayor of Mariagerfjord, a northern town, told the national broadcaster that he would disregard the law and accept a nod or a bow from an applicant refusing to extend her hand. "But I think it's a hypothetical question I'll never face," he said.

In Ishoj, a suburb of Copenhagen, immigrants and their descendants constitute 40 per cent of the population. Mr Ole Bjorstorp, who has been Mayor for 17 years, said he had never met anybody who refused to shake his hand.

Mr Billy O'Shea, an Irish translator living in Denmark since 1981, is waiting for an answer to his application for citizenship, but said he would give it up if he were forced to shake hands.

"Respect is not something you in a democratic country, can demand by threats," he wrote in an e-mail exchange. "Respect is something that occurs between equal citizens. We can't shake each other's hands if one of us is on our knees."

To gain citizenship in Denmark, an immigrant must have legal residence for up to nine years, pass a Danish language test, have no record of serious crime, be financially self-sufficient, as well as pass a test on Danish politics, history and society.

Ms Stojberg, who is a member of the centre-right Venstre party, told Parliament that municipalities would face fines if they did not abide by the handshake law.

A spokesman for the Council of Appeal, which oversees local government compliance with laws, said the mere threat of a fine usually made municipalities comply.

In Aabenraa, Mr Andresen said he regretted Danes' negativity about immigration, noting that the country had successfully integrated refugees from the former Yugoslavia, and had built close ties to Germany, a former enemy.

"I'd be sad to see us portrayed as a xenophobic country and a xenophobic people. Because we absolutely are not," he said. "And we need the workforce."

NYTIMES