Hybrid drivetrain for a tractor comprising: - an internal combustion engine (ICE) having an output shaft (O) connected to a first disengageable joint (C1); - a first electric machine having a first rotor rigidly connected to a drive shaft (D) disconnectable from the output shaft (O) via the first joint (C1); - a second electric machine having a second rotor rigidly connected to a hollow shaft (H) housing the drive shaft (D); - a spacer shaft connected in torque transfer to the drive shaft (D) and disconnectable via a second disengageable joint (C2) from a PTO shaft (P); - a planetary gear having: A first stage crown gear configured to be permanently rotationally fixed; a first stage sun gear rigidly connected to the hollow shaft (H); a plurality of first stage planet gears carried by a second stage crown gear ; a second stage sun gear permanently connected in direct drive to the drive shaft (D); a plurality of second stage planet gears connected in torque transfer to a propulsion device of the vehicle via a second stage carrier; wherein the first electric machine is opposite to the planetary gear with respect to the second electric machine and the internal combustion engine, the first and second electric machine and the planetary gear are frontally joined to define an overall oblong body. - an internal combustion engine (ICE) having an output shaft (O) connected to a first disengageable joint (C1); - a first electric machine having a first rotor rigidly connected to a drive shaft (D) disconnectable from the output shaft (O) via the first joint (C1); - a second electric machine having a second rotor rigidly connected to a hollow shaft (H) housing the drive shaft (D); - a spacer shaft connected in torque transfer to the drive shaft (D) and disconnectable via a second disengageable joint (C2) from a PTO shaft (P); - a planetary gear having: A first stage crown gear configured to be permanently rotationally fixed; a first stage sun gear rigidly connected to the hollow shaft (H); a plurality of first stage planet gears carried by a second stage crown gear ; a second stage sun gear permanently connected in direct drive to the drive shaft (D); a plurality of second stage planet gears connected in torque transfer to a propulsion device of the vehicle via a second stage carrier; wherein the first electric machine is opposite to the planetary gear with respect to the second electric machine and the internal combustion engine, the first and second electric machine and the planetary gear are frontally joined to define an overall oblong body. A first stage crown gear configured to be permanently rotationally fixed; a first stage sun gear rigidly connected to the hollow shaft (H); a plurality of first stage planet gears carried by a second stage crown gear ; a second stage sun gear permanently connected in direct drive to the drive shaft (D); a plurality of second stage planet gears connected in torque transfer to a propulsion device of the vehicle via a second stage carrier; wherein the first electric machine is opposite to the planetary gear with respect to the second electric machine and the internal combustion engine, the first and second electric machine and the planetary gear are frontally joined to define an overall oblong body. <EOS>