Thanks to you both for your replies. I'll try the councillor route if the landlord decides to take no action (which is possible). He seems to be angry about what's been going on, but in the end he's getting a regular income from these tenants, so we're not sure what to expect. The main problem seems to be the agency, who obviously don't want anything to change as they're making money out of the situation too and don't want to rock the boat. We've tried recording everything and taking it to the council, but they seem to only want to take things so far before they give up. They feel we need to be physically threatened before they take action. Anyway, fingers crossed.

My girlfriend and I live in a basement flat which she owns and the rest of the house above is rented out by a large London letting agency (the "F" word). The tenants living above (2 couples) have also had 2 other people living in the living and dining rooms for the past few months and have been noisy and disrespectful (coming in at 4am and playing dance music/raised voices) despite knowing how much it affects us and our neighbours. We've complained to the letting agents on a few occasions but they basically did nothing and haven't even done a house check since february as it turns out. In the end, we've resorted to talking to the actual landlord of the property (who lives a few hundred miles away) who's furious about the way these tenants have been behaving. He spoke to the agents at the start of the week, and they've done nothing. We were woken again at 4:30 this morning and phoned the agents later in the morning, and they still seem to have done nothing as the music is still playing. We've tried environmental health, but it has to be above a certain decibel level for them to do something. It doesn't change the fact that it's bothering the people surrounding them. We're in Hackney, so a lot of this stuff goes on and the council feel things have to be "seismic" with noise before they'll do anything. Just wondered whether anyone else has experienced anything similar and if this kind of failure of management by the agency (these people are obviously breaking their tenancy agreement) is widespread. If somebody knows the responsibilities of the agents and could give me a basic list I'd be grateful.