Think it is means tested and depends on how much you earn etc., but I do know that it doesn't matter whether it is rented from the local council or a private landlord. I think if you are out of work (which I know you aren't) you can also get help towards paying mortgage but as I am not sure about this it would need looking into a bit farther.
If you google rent rebates in England you will find websites which will help you. As I said, it depends on how much you earn and if you have money in the bank - how much - you can have up to £16,000. There are other restrictions but you can have a look yourself and see if you qualify.
You could be buying your house and fall on hard times, bednobs so you will get something to help you. After all, why should people who are paying rent as opposed to people buying be any different. Only the interest though as jem says.
Craftypig - I get a regular news letter every week from Martin Lewis telling me all sorts of things I can save money on. It is very useful and gives lots of moneywise information. Also on his web-site.