A stable catalyst solution suitable for catalyzing the polycondensation of reactants to make polyester polymers comprising: (i) M, wherein M is represented by an alkaline earth metal or alkali metal and (ii) aluminum metal and (iii) a polyhydroxyl ether solvent, wherein the molar ratio of M:Al ranges from 0.2:1 to 4:1 or less. The catalyst solution is desirably a solution which does not precipitate upon standing over a period of at least one week at room temperature (25° C.-40° C.), even at molar ratios of M:Al approaching 1:1. There is also provided a method for the manufacture of the solution, its feed to and use in the manufacture of a polyester polymer, and polyester polymers obtained by combining certain ingredients or containing the residues of these ingredients in the composition.