It was joined by pro-Pierre Mendès-France clubs ( Union of Clubs for the Renewal of the Left led by Alain Savary ) and left-wing republican groups ( Union of Socialist Groups and Clubs of Jean Poperen ) .
It was joined by pro-Pierre Mendès-France clubs ( Union of Clubs for the Renewal of the Left led by Alain Savary ) and left-wing republican groups ( Union of Socialist Groups ad Clubs of Jean Poperen ) .