The French government is to challenge a city council’s decision to allow bathers to wear the burkini – a full-body swimsuit – in its pools. The interior minister, Gérald Darmanin, said the move was an “unacceptable provocation” that was against the values of the secular republic and announced he would seek to block it. Grenoble council’s decision to loosen the strict rules of swimwear to allow people to dress “how they like” at outdoor municipal pools, including wearing burkinis or swimming topless, has reopened the contentious debate over the place of religious symbols and clothing in France just weeks from a legislative election. Critics see the body-covering garment as a symbol of creeping Islamism and an attack on France’s secular tradition while some feminists would like a complete ban, regarding it as a symbol of female oppression. Until now, it has been banned in public pools, along with baggy swim shorts and T-shirts, for reasons of hygiene. The current rules require male bathers to wear tight-fitting trunks. Grenoble’s decision to allow the wearing of burkinis provoked an angry response from opponents. The regional authority announced it was immediately suspending public funding to the city and an investigation has been launched by the public prosecutor into an organisation behind the move. Laurent Wauquiez, of the centre-right Les Républicains party and president of the Auvergne-Rhône-Alpes regional authority, said Grenoble had “broken with secularism and the values of our Republic” and engaged in a form of “separatism”. He had accused the local mayor, the Ecology-Green representative Éric Piolle of “doing deals with political Islam … to buy votes”. Piolle faced fierce opposition against the move and won the swimwear vote by a slim 29 votes to 27, with two abstentions after a fiery debate that lasted almost four hours. Piolle said he was delighted to be attacked by Darmanin, and said the decision was a “feminist one”. “All we want is for women and men to be able to dress how they wish,” Piolle told RMC radio afterwards. Grenoble is not the first to allow bathers to wear burkinis in municipal pools; in 2019, Rennes in north-west France loosened its dress code to allow the full-body swimsuit and other types of swimwear. In 2016, attempts by several mayors to ban the burkini from beaches in the Mediterranean caused a national row and were eventually ruled to be discriminatory. France’s 1905 law on laïcité – which roughly translates as “secularism” – allows the wearing of religious symbols in public places, including swimming pools as long as they do not impinge on hygiene and safety. Muslim female footballers in France are currently engaged in a legal battle to overturn French Football Federation rules that prevent them wearing the hijab. The FFF bans all “ostentatious” religious symbols including the Jewish kippa for competition matches. On Tuesday, the Grenoble public prosecutor opened an investigation into Alliance Citoyenne, the organisation that campaigned for the burkini after allegations that it had illegally “collected and kept” personal information on people’s ethnic origins as well as their political and religious beliefs. The gathering of such information is strictly prohibited in France. The local prefect, the state representative, is also to contest the decision to change the pool dress rules in the administrative court, claiming it contravenes both the 1905 law and legislation passed last August to combat religious “separatism”.