The emerging strength of the far left and far right is creating awkward choices for mainstream parties after the first round of French mayoral elections. There, after round one, the incumbent Socialist Mayor, Benoît Payan, is only a whisker ahead of RN candidate Franck Allisio. But two other candidates have also qualified for round two, with lower scores: the Republicans' Martine Vassal and the LFI's Sébastien Delogu. So should the Socialists enter a pact with LFI in order to save Payan? And should Vassal throw her lot in with RN in order to keep out the left? Electorally the alliances make sense but the flipside is the damage to the mainstreamers' reputation if they cosy up to parties that they normally condemn. Under its leader, Jean-Luc Mélenchon, LFI formed an alliance with the PS, Greens and Communists to give the left a strong showing in the last legislative election in 2024. All this makes impossible any formal alliance with LFI, which is why on Sunday evening PS leader Olivier Faure ruled out any "national" accord to join forces in next Sunday's second round.