hasbean, you seriously need to sort this out. I don't want to scare you, but the ultimate sanction for non-payment of council tax is imprisonment. If you show real willing to negotiate they are highly highly unlikely to push for imprisonment, but if you pay them as an when...put it this way, thats not what they're looking for.
Also, you are going to end up paying for the baliffs visits-they are added to your bill.
Ultimately they will take you to court (at your expense) and the court will probably order you to pay a certain amount each week. So you might as well make them an offer now.
Personally, I'd get yourself to the lovely CAB, and get them to urgently help you work out how much you can offer. Do you have other debts?
now I admit that I have been on ML for a year, but I doubt the law here has changed much. This is the kind of situation that should be fasttracked by the cab.
am not trying to scare you, i know its horrible and scary, i know...but honestly, it has the potential to get much worse.
Seriously, get in touch now with them