Former French president Nicholas Sarkozy said on Monday he would change the country's constitution to ban full-body burkini swimsuits if he is re-elected to his former role in a vote next April.

Positioning himself as a defender of French values and tough on immigration, the conservative said last week that he would impose a nationwide ban on the swimwear that has divided the Socialist-led government and dominated French political debate through much of August.

France's highest administrative court suspended on Friday a ban on burkinis that had spread to a dozen French coastal cities on the grounds they violated fundamental liberties.

The burkini bans have exposed secular France's difficulties grappling with religious tolerance after Islamist militant attacks in a Normandy church and the Riviera city of Nice in July. Images of armed police apparently enforcing the ban on a woman on a beach in Nice have added to the controversy.

The bans had been justified on public order grounds, and Socialist Prime Minister Manuel Valls appeared to defend the town officials who imposed them.

After the court set the bans aside, however, Interior Minister Bernard Cazeneuve said a law against the garments would be ruled unconstitutional.

Asked about that risk, Sarkozy said: "Well, then we change the constitution. We've changed it thirty odd times, it's not a problem."

Sarkozy is struggling to catch up in the polls with rival Alain Juppe, a mild-mannered, more centrist former prime minister before their Republicains party's primary elections in late November.

Cazeneuve, who was meeting with French Muslim leaders on Monday to ease religious tensions, said he would name veteran politician Jean-Pierre Chevenement to head an independent body charged with handling relations between the state and the religion's representatives.