A cutting tool comprising a tool holder and a cutting insert, the tool holder comprising opposite first and second side surfaces (108, 110), and an insert pocket having a longitudinal main axis extending in a forward to rearward direction (D F, D R) and a lateral pocket axis, with a pocket screw bore passing through the insert pocket along the pocket axis; the insert pocket comprises: a forward clamping portion coupled with the second side surface, located forward of the pocket axis, and having a forward abutment surface; and a rear clamping portion coupled with the first side surface, located rearward of the pocket axis, and having first and second rear abutment surfaces (130, 132); the cutting insert having a longitudinal first axis and a lateral second axis, and comprising two end surfaces and a peripheral surface therebetween, the cutting insert having two opposite cutting portions, a first cutting portion and a second cutting portion, and a clamping portion therebetween, arranged along the first axis, each cutting portion having a cutting edge, the cutting insert having an insert screw bore passing through the clamping portion along the second axis, the cutting insert having 180° rotational symmetry about the second axis; wherein the cutting insert peripheral surface has two opposing side flanks, a first side flank extending partially along the clamping portion and along the first cutting portion, and a second side flank extending partially along the clamping portion and along the second cutting portion, the clamping portion is provided with two first and second clamping surfaces (138, 140) located on the cutting insert peripheral surface, each second clamping surface located adjacent a respective side flank, and both of the second clamping surfaces located longitudinally between the first clamping surfaces; characterised in that in an assembled position of the cutting tool the first and second clamping surfaces (138, 140) adjacent one side flank abut the first and second rear abutment surfaces (130, 132), respectively, the first clamping surface adjacent the other side flank abuts the forward abutment surface, and neither of the side flanks abuts the tool holder. the tool holder comprising opposite first and second side surfaces (108, 110), and an insert pocket having a longitudinal main axis extending in a forward to rearward direction (D F, D R) and a lateral pocket axis, with a pocket screw bore passing through the insert pocket along the pocket axis; the insert pocket comprises: a forward clamping portion coupled with the second side surface, located forward of the pocket axis, and having a forward abutment surface; and a rear clamping portion coupled with the first side surface, located rearward of the pocket axis, and having first and second rear abutment surfaces (130, 132); a forward clamping portion coupled with the second side surface, located forward of the pocket axis, and having a forward abutment surface; and a rear clamping portion coupled with the first side surface, located rearward of the pocket axis, and having first and second rear abutment surfaces (130, 132); the cutting insert having a longitudinal first axis and a lateral second axis, and comprising two end surfaces and a peripheral surface therebetween, the cutting insert having two opposite cutting portions, a first cutting portion and a second cutting portion, and a clamping portion therebetween, arranged along the first axis, each cutting portion having a cutting edge, the cutting insert having an insert screw bore passing through the clamping portion along the second axis, the cutting insert having 180° rotational symmetry about the second axis; wherein the cutting insert peripheral surface has two opposing side flanks, a first side flank extending partially along the clamping portion and along the first cutting portion, and a second side flank extending partially along the clamping portion and along the second cutting portion, the clamping portion is provided with two first and second clamping surfaces (138, 140) located on the cutting insert peripheral surface, each second clamping surface located adjacent a respective side flank, and both of the second clamping surfaces located longitudinally between the first clamping surfaces; characterised in that in an assembled position of the cutting tool the first and second clamping surfaces (138, 140) adjacent one side flank abut the first and second rear abutment surfaces (130, 132), respectively, the first clamping surface adjacent the other side flank abuts the forward abutment surface, and neither of the side flanks abuts the tool holder.