Just over a year ago i posted how my car was like new. Well two weeks after the same problem happened and silly old me i left it. It turns out the reason again is due to the seal inside the gearbox. The fluid is leaking out all over the bottom of the gearbox. If any of you have a problem with your clutch slipping i would advise you getting these seals changed. My car is now at the stage where its very difficult to drive and i am in a dispute with the garage that carried out the work.
So in short it will be the seals!!