The son of two Labour MPs was jailed yesterday for beating up his girlfriend.

Stuart Morgan, 28, adopted son of Cardiff West MP Rhodri Morgan and Cardiff North MP Julie Morgan, admitted assaulting Natalie Dickson, 23, damaging her car and possessing an offensive weapon.

Mature student Morgan attacked Ms Dickson in her car, and demanded to know who she had been with during an even ing out, Cardiff Crown Court heard.

Hugh Wallace, prosecuting, said: ''He grabbed her by the throat and squeezed very hard. She began to choke. She became aware of a knife which was pressed up against her cheek. He then pushed it close to her eyes and said: 'Tell me'.''

The court heard Morgan slashed the passenger seat and kicked in the back window. Ms Dixon was grabbed by the hair, dragged out of the vehicle and thrown against a wall. Morgan then head-butted her in the face.

Greg Taylor, defending, said Morgan had split amicably with Ms Dickson. Judge William Gaskell jailed Morgon for three months.