An activator precursor composition comprising: i) a support material in contact with a linking compound, and ii) a polyfunctional compound which has at least two aromatic groups in which at least two of said aromatic groups each has at least one polar monoprotic group thereon, wherein the linking compound is an organometallic compound, a nonorganometallic compound or mixtures thereof, wherein when the linking compound is an organometallic compound, it has the formula: MR 1 s Q t-s wherein M represents a metal atom selecting from Mg, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Zn, B, Ga, In, Sn and mixtures thereof; R 1 may be the same or different and represents a C 1 -C 20 hydrocarbyl group, wherein the beta carbon of the hydrocarbyl group may be replaced by Si; Q represents a hetero-atom or a heteroatom containing organic group where the heteroatom is directly bonded to M via the heteroatom; t stands for the valence of M and s is a number such that 2 ≤ s ≤ t, and when the linking compound is a nonorganometallic compound, it is represented by the formula: M 1 Q 1 t wherein M 1 represents a metal atom selecting from Mg, Al, Sc, Y, Zr, Hf, V, Nb, Ta, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B Ga, In, Al, Si, Ge, Sn, La, Ce, Er, Yb, Lu and mixtures thereof; Q 1 may be the same or different and represents a heteroatom or a heteroatom containing organic group where said heteroatom or heteroatom containing group is directly bonded to M 1 via the heteroatom; t stands for the valence of M 1 , or MgCl 2 , MgF 2 , AlCl 3 , AlF 3 , SiCl 4 , SiMeCl 3 , SiMe 2 Cl 2 , Ti(OEt) 4 , Ti(OBu) 4 , Ti(NMe 2 ) 4 , Ta(NMe 2 ) 5 or Zr(NMe 2 ) 4 . i) a support material in contact with a linking compound, and ii) a polyfunctional compound which has at least two aromatic groups in which at least two of said aromatic groups each has at least one polar monoprotic group thereon, wherein the linking compound is an organometallic compound, a nonorganometallic compound or mixtures thereof, wherein when the linking compound is an organometallic compound, it has the formula: MR 1 s Q t-s wherein M represents a metal atom selecting from Mg, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Zn, B, Ga, In, Sn and mixtures thereof; R 1 may be the same or different and represents a C 1 -C 20 hydrocarbyl group, wherein the beta carbon of the hydrocarbyl group may be replaced by Si; Q represents a hetero-atom or a heteroatom containing organic group where the heteroatom is directly bonded to M via the heteroatom; t stands for the valence of M and s is a number such that 2 ≤ s ≤ t, and when the linking compound is a nonorganometallic compound, it is represented by the formula: M 1 Q 1 t wherein M 1 represents a metal atom selecting from Mg, Al, Sc, Y, Zr, Hf, V, Nb, Ta, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B Ga, In, Al, Si, Ge, Sn, La, Ce, Er, Yb, Lu and mixtures thereof; Q 1 may be the same or different and represents a heteroatom or a heteroatom containing organic group where said heteroatom or heteroatom containing group is directly bonded to M 1 via the heteroatom; t stands for the valence of M 1 , or MgCl 2 , MgF 2 , AlCl 3 , AlF 3 , SiCl 4 , SiMeCl 3 , SiMe 2 Cl 2 , Ti(OEt) 4 , Ti(OBu) 4 , Ti(NMe 2 ) 4 , Ta(NMe 2 ) 5 or Zr(NMe 2 ) 4 . <EOS>