The national office of the party chaired by deputy Jean-Christophe Lagarde adopted this position "unanimously", according to a press release.
The UDI wants "a mandate very different from the first rather than the risk of collapse that the far-right program carries".
"For the first time, the far-right candidate can win," alarmed the centrist party.
"Nothing in his program resembles our values or the projects that we carry", he added, listing "his positions on Europe", "his closeness to authoritarian regimes" or "his economic proposals demagogic".
"She has no team with the skills and experience to govern, even by allying with Eric Zemmour," added the party.
He invites Emmanuel Macron to "take France much more into account, which suffers from social inequalities and (the) lack of territorial equity".
The UDI had given its support in January to the candidate LR Valérie Pécresse, eliminated in the first round with 4.78% of the votes cast.
© 2022 AFP