Politicians in Venezuela say their attempts to form an alliance against the presidential candidate and ex-colonel, Hugo Chavez, have failed.

Mr Chavez, who led a coup attempt in 1992, is currently ahead in the opinion polls for December's presidential election.

The Christian and Social Democrat parties had been discussing joining forces against Mr Chaves.

But members of both parties now say they're unwilling to back his nearest rival, the independent candidate, Henrique Salas, because it will ruin any chance of their own party leaders becoming president.