Visa for one employer, can I work for another too?

My work visa is renewed yearly and states the company and position it is linked to.
In my current situation of reducing to part-time, I wish to pick up secondary employment.

Anyone know if this is allowed on my current visa?

Many thanks,
Howard

(p.s. I've been tacking this question on to related threads for a while now with no responses, please excuse the repetition elsewhere)

It is not.. One Visa/One Employer. If you want it changed your going to have to goto the KVR

Darkknight is right (though he usually is).
This happened to me- got a new job last year and had to get an entire NEW visa with both jobs listed on it. Same procedure. Same paperwork. Same waiting game. Same idiots at the KVR.
Good luck

Cheers for the replies.. It was somewhat an expected answer, but I try to believe in the occasional miracle.

Another thing...

My potential secondary employer is rather weary of getting involved in this process.

Does anyone know what is actually required of them, other than a letter stating the Job description & requirements?

Can I take the load/worry off my employer to get this processed?