Small Mortgage against part owned house

Hi guys,

I was wondering if anyone can point me in the right direction, or tell me if i'm wasting my time.

I own a third of a house (other 2 thirds owned by sibling and parent) worth approximately £165,000 (so my share worth around £55,000). The house is mortgage free and is let via an estate agent.

I was wondering if I could secure a mortgage against my third of the property, for around £25,000. This would be to pay off car finance and credit card.

My annual wage is a guaranteed £18,000 before OT or bonus.

Is this likely/possible? and where would the best placed be to start? Or is it a wild goose chase?

Thanks

Rickatron