A process for the preparation of an elastomeric polymer of ethylene which comprises polymerizing, in suspension, a mixture of monomers comprising ethylene, at least one α-olefin having from 3 to 12 carbon atoms, possibly at least one non-conjugated diene having from 4 to 20 carbon atoms, in the presence of a catalytic system in which there are no organic solvents present, comprising: - a suspension in oil of at least one catalyst selected from compounds containing vanadium; - at least one co-catalyst, used in the absence of organic solvent, selected from compounds containing aluminium; - at least one activator, used in the absence of organic solvent, selected from compounds containing chlorine having general formula: wherein: - R 2 represents a linear or branched C 1 -C 20 alkyl group, optionally substituted; a C 5 -C 20 aryl group, optionally substituted; a C 3 -C 20 cycloalkyl group, optionally substituted; with the proviso that the group -C OR 2 can be substituted with a derivative of carbonic acid, a keto group or a nitrile group; - R 3, R 4 and R 5, the same or different, are selected from: (a) R 2; (b) halogens such as chlorine, bromine, fluorine, iodine; (c) hydrogen; (d) linear or branched C 1 -C 20 alkyl groups, optionally substituted; (e) C 3 -C 20 cycloalkyl groups, optionally substituted; (f) C 5 -C 20 aryl groups, optionally substituted; (g) C 1 -C 20 alkyloxyl groups, optionally substituted; (h) C 5 -C 20 aryloxyl groups, optionally substituted; (i) -C OR 6 groups wherein R 6 is a C 1 -C 20 hydrocarbon group; with the proviso that: (ii) at least one of R 3, R 4 and R 5 is selected from halogens (b), and (iii) in the activator having formula, all the following conditions are not satisfied: R 2 is a C 1 -C 6 alkyl group, R 3 is a C 1 -C 6 alkyl group or a C 1 -C 6 alkoxyl group, R 4 is chlorine, bromine or hydrogen, R 5 is chlorine or bromine. - a suspension in oil of at least one catalyst selected from compounds containing vanadium; - at least one co-catalyst, used in the absence of organic solvent, selected from compounds containing aluminium; - at least one activator, used in the absence of organic solvent, selected from compounds containing chlorine having general formula: wherein: - R 2 represents a linear or branched C 1 -C 20 alkyl group, optionally substituted; a C 5 -C 20 aryl group, optionally substituted; a C 3 -C 20 cycloalkyl group, optionally substituted; with the proviso that the group -C OR 2 can be substituted with a derivative of carbonic acid, a keto group or a nitrile group; - R 3, R 4 and R 5, the same or different, are selected from: (a) R 2; (b) halogens such as chlorine, bromine, fluorine, iodine; (c) hydrogen; (d) linear or branched C 1 -C 20 alkyl groups, optionally substituted; (e) C 3 -C 20 cycloalkyl groups, optionally substituted; (f) C 5 -C 20 aryl groups, optionally substituted; (g) C 1 -C 20 alkyloxyl groups, optionally substituted; (h) C 5 -C 20 aryloxyl groups, optionally substituted; (i) -C OR 6 groups wherein R 6 is a C 1 -C 20 hydrocarbon group; with the proviso that: (ii) at least one of R 3, R 4 and R 5 is selected from halogens (b), and (iii) in the activator having formula, all the following conditions are not satisfied: R 2 is a C 1 -C 6 alkyl group, R 3 is a C 1 -C 6 alkyl group or a C 1 -C 6 alkoxyl group, R 4 is chlorine, bromine or hydrogen, R 5 is chlorine or bromine. - at least one activator, used in the absence of organic solvent, selected from compounds containing chlorine having general formula: - R 2 represents a linear or branched C 1 -C 20 alkyl group, optionally substituted; a C 5 -C 20 aryl group, optionally substituted; a C 3 -C 20 cycloalkyl group, optionally substituted; with the proviso that the group -C OR 2 can be substituted with a derivative of carbonic acid, a keto group or a nitrile group; - R 3, R 4 and R 5, the same or different, are selected from: (a) R 2; (b) halogens such as chlorine, bromine, fluorine, iodine; (c) hydrogen; (d) linear or branched C 1 -C 20 alkyl groups, optionally substituted; (e) C 3 -C 20 cycloalkyl groups, optionally substituted; (f) C 5 -C 20 aryl groups, optionally substituted; (g) C 1 -C 20 alkyloxyl groups, optionally substituted; (h) C 5 -C 20 aryloxyl groups, optionally substituted; (i) -C OR 6 groups wherein R 6 is a C 1 -C 20 hydrocarbon group; with the proviso that: (ii) at least one of R 3, R 4 and R 5 is selected from halogens (b), and (iii) in the activator having formula, all the following conditions are not satisfied: R 2 is a C 1 -C 6 alkyl group, R 3 is a C 1 -C 6 alkyl group or a C 1 -C 6 alkoxyl group, R 4 is chlorine, bromine or hydrogen, R 5 is chlorine or bromine. (ii) at least one of R 3, R 4 and R 5 is selected from halogens (b), and (iii) in the activator having formula, all the following conditions are not satisfied: R 2 is a C 1 -C 6 alkyl group, R 3 is a C 1 -C 6 alkyl group or a C 1 -C 6 alkoxyl group, R 4 is chlorine, bromine or hydrogen, R 5 is chlorine or bromine.