MADRID — Manuel Valls wants to change the rules.

The former French prime minister is challenging the view that European politics remains a stubbornly national business.

“I want to become the next mayor of Barcelona,” he told a crowd Tuesday in the Catalan capital, announcing a candidacy that had been in the making since April.

Valls — who was born in Barcelona, grew up in France and is a French citizen — will run what he called an independent, non-partisan candidacy aiming to seize power from the current leftist mayor, Ada Colau, in local elections in May 2019.

No one better to defeat separatism and populism at the ballot box" — Ciudadanos leader Albert Rivera

There have been politicians elected in two European countries – such as Franco-German former MEP Daniel Cohn-Bendit — and many EU nationals compete in local ballots in countries that aren't their own.

But no other former head of government in the EU has run for office in a different country.

“This is the dream of Europe,” Valls said. “We have the opportunity to be the first.”

Speaking in slightly accented Spanish and Catalan — and some French — Valls spoke about his origins in Barcelona (his father was a Catalan painter exiled under the dictatorship of Francisco Franco) and his love for Catalan culture and language, which he said was spoken at home after the family moved to France.

“Some [Barcelona] citizens consider it an honor that a former French prime minister comes to compete for the mayorship,” said Oriol Bartomeus, a politics professor at the Autonomous University of Barcelona. “But others have the opinion that he may have a very superficial knowledge of the city.”

Muchas gracias, @manuelvalls, por aceptar este reto. Nadie mejor para recuperar el prestigio de Barcelona y derrotar al separatismo y al populismo en las urnas. Es una gran noticia para nuestra ciudad, para España y para toda Europa. Endavant! https://t.co/y4UiSfUrzr — Albert Rivera (@Albert_Rivera) September 25, 2018

Valls is targeting both Catalan unionist voters — the liberal, pro-unity Ciudadanos, which offered him the chance to be the head of its local list, has thrown its weight behind his independent candidacy — and moderate, affluent nationalists tired of what he described as the “grave problems” of the city; namely, insecurity, drugs and illegal street vendors.

Albert Rivera, the leader of Ciudadanos, congratulated Valls on Twitter immediately after his speech: “No one better to defeat separatism and populism at the ballot box. It’s great news for our city, for Spain and for Europe,” he said.

Valls became involved in Spanish politics after his failed bid for the leadership of the French Socialist Party and at the peak of the Catalan independence push last year. His tough words against separatism — “unmaking Spain is unmaking Europe,” he said — played well with pro-unity audiences in Catalonia and the rest of Spain.

He became an instant hit on Spanish TV shows, received several awards and even got invited to address hundreds of thousands of demonstrators rallying for a united country in Barcelona in March this year. He also became involved with pro-unity organization Societat Civil Catalana, some of whose members have been promoting his candidacy.

However, Valls seems to know that he must broaden his appeal if he’s to stand a chance of becoming mayor. Although he vowed on Tuesday to fight “nationalism and populism,” he said he wanted to become the mayor of everyone, pro- and anti-independence.

“He needs to build up a platform which ... goes beyond Ciudadanos voters,” said Bartomeus, the politics professor.

The Frenchman won't have an easy ride to the mayorship of a city that Catalan separatists consider must be retaken after their failed bid for secession last year.

“I want to have a pro-independence mayor in Barcelona,” Catalan President Quim Torra told POLITICO in an interview earlier this month. “This is one more of the lessons of last October,” he added, arguing that such a mayor could’ve acted as “the leader of the country” when the region was put under the control of the central government.

Another obstacle for Valls is Colau. The anti-establishment mayor, who seized power in 2015 thanks to an alliance of various groups including the far-left Podemos, didn’t wait for Valls to confirm his candidacy to start hammering him. She’s portrayed him as a right-wing “reactionary,” someone unfamiliar with the city and a loser.

His “political career has failed in France,” she said in April.

Valls served as interior minister (2012-2014) and then prime minister (2014-2016) in France under Socialist President François Hollande. In 2017, he lost in the Socialist Party primaries and refused to endorse the winner, Benoît Hamon. Later that year, he attempted to join President Emmanuel Macron’s En Marche movement but was rejected.

Much is still unknown about Barcelona’s mayoral ballot, with not all candidates having declared. Some secessionists are calling for a common pro-independence ticket and others are resisting the pressure. Even if Valls ends up as the most popular candidate, a potential alliance of pro-independence parties or one of Colau and other leftist groups could deprive him of power.

What is clear is that Barcelona’s local ballot, which has already been dubbed “The Battle for Barcelona,” is going to be one of the most exciting political contests in Spain for some time.