Sponsorship to work in a TV Production Management position in the UK?

I'm Australian and have already completed my 2 year working holiday visa in the UK (was based in London, working on various factual shows).
I'm now back in Aus and looking to return but it just seems impossible to try and get sponsored as a PM when most roles offered are on short contracts. Has anyone been successful obtaining sponsorship for a production management role, and kindly have any advice to share?