RTB, Freehold and service charges?

strawb_shortcake

I'm currently going through the Right to buy process, we've had the mortgage offer and it's currently with the solicitors, however on the 125 letter from the Housing Association (previously we were with the council hence RTB and not RTA) it states that there may be A potential service charges in the future for grass/hedge cutting, bulk removal and litter picking, and they may introduce this at any time in the 5 years preceeding our purchase.

This does not seem right to me, a flick through the Housing Act 1985 seems to refer more to leasehold properties flats and maisonettes, the street we live on 50% of the houses are privately owned, there is no communal areas or grass areas, the only hedgerow is on farm land owned by a private estate (An Earl, so definitley not the local council) and there are also no flats or maisonettes. Presumably the responsibility of the road lies either with the highway agency or council?

Can anyone advise if I have good ground to ask for this to be removed? Or know what bit of legislation I should be looking at?
I know I should be asking my solicitors but they are incredibly difficult in getting through to them, so would like to be able go to either them or the HA with something solid