Paris will choose a new mayor on Sunday, with one unlikely issue dominating campaigns alongside all the partisan acrimony - dogs.

Candidates from socialists to conservatives have set out policies to deal with an issue which voters have regularly ranked among their top concerns, a lack of space for the capital's estimated 100,000 canines.

"Paris isn't exactly a very dog-friendly capital," said Vincent Danna, founder of the Monceau Dog Club, a group of around 1,000 owners who have campaigned for more open spaces for their pets.

"It can indeed be a decisive factor in municipal elections. I think the candidates have understood that well."

Rachida Dati, the conservative candidate backed by President Emmanuel Macron, has filmed herself with dogs on the campaign trail and told Reuters she would create new parks where owners can take their dogs for walks, or even let them run free.

"We're going to develop dog parks specifically to create these shared spaces. And not just for the sake of shared spaces, but so people can bring their pets along freely, without being bothered or judged. That's the idea," Dati said.

Socialist Emmanuel Gregoire, who led the first round of voting last Sunday, has also committed to expanding outdoor spaces for pets.

"The main goal is to have outdoor spaces where animals can live as comfortably as possible," Gregoire told Reuters.

Sophia Chikirou, from the hard-left LFI party who came third in the first round, has proposed letting owners take their dogs on all forms of public transport.

Pets have long played a role in French political life. Every president since Charles de Gaulle has owned at least one dog. Far-right leader Marine Le Pen studied to get a cat-breeding diploma in 2021.

An Ifop poll in February showed 58% of French voters saw animal welfare as a priority issue in their municipality. So far, activists have taken the lead.

Following pressure from the Monceau Dog Club, the park of the same name has let dogs run free in a dedicated area in the first trial of its kind in the capital.

Still, not everyone is convinced dogs will make a difference in the second and final round of voting this weekend.

"If you ask me whether a dog plan is going to sway my vote one way or the other, I would say no. Because I think there are perhaps more important things," local resident Marie-Christine Alary said.

"But I do think it's a very good thing."