i have a opel astra 2003 1.4 and it jerks while driving..?

[HristoK]

it jerk mostly when the car is cold. and when starting off at lights it feels like its struggling to go but when the engine gets hot its fine. this is a video off what happens when i am driving. could anyone help me to identify what the problem is .
Thanks
http://www.youtube.com/watch?v=dcUftouKIP4