Prime Minister Silvio Berlusconi called on centrist elements of Italy's political opposition on Tuesday to join him in his race for re-election, an invitation rejected as "pathetic" by one of the main centre-left parties, Reuters said. Berlusconi, whose centre-right government includes ex-fascists, claims he represents Italy's moderate majority better than the opposition, led by former European Union chief Romano Prodi, which is home to former and current communists. "I invite moderates from the Margherita (the second biggest opposition party) who are ill at ease in an alliance with the extreme left: leave that unnatural arrangement and build with us a big house of moderates," Berlusconi said at a meeting of his Forza Italia (Go Italy) party. The provocative invitation comes as the centre-left is bickering over how to approach the election due by next May, leading Prodi to threaten to quit unless others fall into line. Prodi wants a single centre-left bloc list for the 25 percent of parliamentary seats decided by proportional representation. The Margherita (Daisy) party has refused, saying the centre-left can gain more votes with individual party lists. --More 2301 Local Time 2001 GMT