The present invention relates to a crosslinkable polymer composition comprising (A) a high density ethylene homo- or copolymer having a density, determined according to ISO 1183, of at least 930 kg/m3, and (B) a copolymer of ethylene with a silane groups-containing comonomer having a content of silane groups-containing comonomer of not more than 4.0 wt %, wherein the polymer composition passes the tracking resistance test, determined according to IEC60587 (2007), method 2A at 4.5 kV for 1 h and 4.75 kV for 1 h on compression molded plaques prepared according to ISO 11357. The present invention further relates to a track resistant wire or cable, preferably a power cable or an optical cable comprising at least one layer of the above polymer composition or to the use of the polymer composition in a wire or cable for increasing track resistance, and/or for increasing fire retardancy along the length of the wire or cable. The present invention further relates to a method for manufacturing the above polymer composition, comprising a step of compounding or dry blending the high density ethylene homo- or copolymer (A) and the copolymer of ethylene with a silane groups-containing comonomer (B).