Residents have complained of a "lake" of raw sewage seeping up to their front doors.

Several families in Stanford Terrace, Hassocks, say the problem has been going on for two years and is making them ill.

Environmental officers have blamed the problem on a tree's roots obstructing the sewage system.

Su Lewis said: "My downstairs neighbour is suffering from ill health anyway which is exacerbated by stress and she's just at her wits' end.

"Now I'm ill as well. I couldn't say if it's related but I certainly wouldn't want to go downstairs today because I don't think my stomach could stand what I'll find there.

"Normally at least half of our gravel drive is literally a lake of effluent."

Ms Lewis said problems began at the flats in Station Approach when the lower part of their Victorian building was being converted two years ago.

An old stable house at the back of the property was converted and neighbours began to notice the smell of untreated waste lingering outside their homes.

Ms Lewis said: "Then a few weeks ago my downstairs neighbour thought someone had been vomiting outside her back door.

"We soon realised that what she was seeing had actually come up through the drains.

"When the nearby manhole floods it comes right to her door. It's absolutely disgusting. There has even been a pool of it dripping down into the road."

The neighbours called out an environmental health officer who confirmed there was a problem with blocked drains, possibly caused by the nearby tree.

Ms Lewis and her neighbours have been advised not to wash or flush their toilets while the effluent was pooling outside.

Yesterday, tankers had to pump out the drains for the second time in two weeks.

Despite the involvement of West Sussex County Council and property managers Property Consultant and Management Ltd, neighbours say the problem remains unsolved.

Ms Lewis said: "They emptied the drain last week and took the water away but all the material was left to sink back down into the drains and the drive.

"It was easily identifiable as toilet matter and tissue and the drains have been constantly overflowing all weekend.

"People are squabbling over whose problem it is. My point is that it's their duty to take immediate action. They can squabble about whose insurance can cover it afterwards.

"It's a health hazard. There are people walking by here every day on their way to the train station who could also be liable to contamination."

Mark Harrington, of Property Consultant and Management Ltd, said: "We've been on site this morning and are doing as much as we can to sort the problem out.

"There's some tree roots that are blocking the drain and we are waiting for the council to confirm what they can do.

"I have sympathy for all the leaseholders and we are doing our utmost to resolve this as quickly as possible.