French Human Rights League lawyer Patrice Spinosi on Saturday vowed to take legal action against any council that keeps the ban, following the Council of State's ruling that Villeneuve-Loubet's ban was a "serious and manifestly illegal violation of fundamental freedoms".
"I can't understand why these politicians continue to take part in a polemic which should never have taken place," he told France Inter radio.
Villeneuve-Loubet's mayor, Lionel Luca, who is also a right-wing MP, said he would comply with the ruling because "I'm not a rebel" but called for a nationwide law against the Islamic swimsuit.
But several of his colleagues have vowed not to scrap the ban.
The mayor of the Channel resort of Le Touquet on Saturday argued that the Council of State's decision only "partly invalidated" his own bylaw, whose wording was different.
Daniel Fasquelle, a lawyer by training, said that, while Villeneuve-Loubet had been found not to have established a "proven risk" to public order, his decree forbade covering faces on the beach so as to ensure that CCTV surveillance could work and banned protected health and safety by stopping people bathing in clothes that could prove dangerous if they were caught in strong currents.
The city council in Nice, where 84 people were killed in a truck attack on Bastille Day, said it would "continue to fine" women wearing the burkini and the National Front mayor of nearby Fréjus, said his ban was "still valid" because no legal challenge had been launched against it.
Ange-Pierre Vivoni, Socialist mayor of the Corsican town of Sisco, said his burkini ban, introduced after a confrontation between Moroccan-origin bathers and locals, would also remain "for the safety of property and people in the town because there was a danger of my having deaths on my hands".
Several of the orders may never be challenged because they run out at the end of the month or in mid-September.
Valls says debate not over
Rights groups welcomed the Council of State ruling.
Abdallah Zekri, of the CFCM coalition of Muslim groups, called it a "victory for the law and good sense, while Amnesty International's Europe director John Dalhuisen said that the French authorities should "drop the pretence" that the ban was about protecting women's rights.
But in a Facebook post Valls declared that the ruling "does not deprive mayors of this right" but simply "reminds [us] of the conditions for its use".
Nor does it "exhaust the debate" on the burkini, the prime minister argued, asserting that the swimsuit is "not a religious sign but the confirmation in the public sphere of political Islam" and that "remaining silent is a small renunciation" as France's "republican pact shatter under the weight of communautarism and the xenophobic reflexes it gives rise to".
Earlier Interior Minister Bernard Cazeneuve had struck a different note, calling for "appeasement, the only way to avoid disturbances to public order and encourage living together".
Calls for national legislation
Valls has ruled out passing a law at national level, which could lead to resignations from the government since Education Minister Najat Vallaud-Belkacem and Health Minister Marisol Touraine have criticised the ban.
Several figures on the right have called for a nationwide ban, among them National Front leader Marine Le Pen and former president Nicolas Sarkozy, who hopes to stand again for the Republicans party next year.
One of Sarkzoy's rivals to become the mainstream right candidate, former prime minister François Fillon, told Le Monde newspaper that he would back such a move "because we can't leave the police alone" to judge what action to take.
But another, former prime minister Alain Juppé whom polls tip to be the favourite, has come out against a law.
Although he did not oppose the local bans, Juppé told Le Figaro newspaper that "we would all do well to stop pouring oil on the fire".
Another Republicans presidential hopeful, Frédéric Lefebvre, also opposed legislation.
"In the present circumstances it would be impossible to draft a law," he told members of the party's youth wing, meeting in Le Touquet this weekend.
To read our coverage of France's burka ban click here