Francois Bayrou, an ally of French President Emmanuel Macron, said on Sunday that he was prepared to give his signature to help Macron's archrival far-right candidate Marine Le Pen, to stand in April's presidential election.
Bayrou, a centrist and historic figure in French politics, said his move came in an effort to "save democracy", as some candidates, including Le Pen, were struggling to obtain the 500 signatures from elected officials needed to submit a valid bid.
"I have decided (...) - and this is really not my dream when it comes to political engagement - to give my signature to Marine Le Pen", Bayrou told RTL radio on Sunday.
According to French election rules, the signatures are made public, deterring many of France's over 40,000 elected officials to support their candidates despite sharing their views, especially when it comes to the far-right or far-left.
Le Pen, who challenged Macron in the second round of the 2017 elections but has seen her third bid for the Elysee Palace suffer setbacks following a wave of defections from her party and the suspension of her campaign spokesman thanked Bayrou in a tweet.
"Despite our political disagreements, his approach aims to keep our democracy alive", she said.
Bayrou earlier this month created what he calls a "sponsorship bank", joined by a few hundred local officials, willing to give their signatures to candidates struggling to obtain them, even if they represent a large part of the public according to opinion polls.
The mayor of the rural town of Pau, whose MoDem party accounts for a seizable chunk of President Macron's parliamentary majority, Bayrou said that many thought the rule was unfair.
"Officials, in particular mayors, are wary their signature will be seen as an endorsement", he said. "This is why we decided to make them sign a declaration which says this is for saving democracy, our signature is no endorsement."
(Reporting by Tassilo Hummel; editing by Emelia Sithole-Matarise)