France’s Socialists on Monday launched a last-ditch appeal for support from other opposition parties in an attempt to avert a crushing defeat on Sunday in the second round of parliamentary elections.

Ségolène Royal, the former Socialist presidential candidate, said she would seek an alliance with François Bayrou’s centre party, the Democrat Movement. But her damage limitation exercise highlighted the weakness of the left and the relative dominance of President Nicolas Sarkozy and his centre-right UMP party.