SOUTHERN Water has been named the worst performing company in the industry for the fourth year running.

The water and sewage firm has had a rise in written complaints from customers of more than 10 per cent in one year.

The main source of complaints were about bills.

The Consumer Council for Water (CCWater) said Southern, which provides services for four and a half million people across Sussex, Kent, Hampshire and the Isle of Wight, had failed to completely get to grips with its problems and has told it to improve its service.

The report said: “At more than 77 complaints per 10,000 connections this level of complaint remains more than twice the industry average, and the gap between Southern and the rest of the industry is widening.

The company has a lot of work to do to close that gap.

Affinity Water, which covers several counties in the south east, also come in for criticism from the watchdog in a report published today, after it emerged it had one of the biggest rises in complaints – 82 per cent – leaving it at the bottom of the pile of water only companies.

The figures are based on complaints received during the 2015/6 financial year.

CCWater London and south east chairman Tony Redmond said he was disappointed by the performance of Southern and Affinity.

He said: “I have written to both companies and asked them to report back to me by the end of October on what action they have taken, or are planning to take, to reduce complaints. We want to see that progress is being made.”

The news was better for South East Water, which also covers parts of Sussex, which say its complaints drop by 38 per cent.

Southern Water said the number of complaints received about the company's water services were amongst the lowest in the industry, however billing complaints pushed the Worthing-based business into the bottom spot overall.

However it said it continued to perform well in health and safety, leakage and drinking water quality and there had been a significant drop in the number of sewer flooding and pollution incidents across its region.

Director Simon Oates said: "We accept there is still much more for us to do to come in line with the rest of the industry and we are continuing to work with CCWater to drive forward further improvements.

“We want to reassure our customers we remain fully committed to continuing the improvements we have already made, and bringing our performance up to the standard they quite rightly expect from us.”

Mr Oates said that since last November, its performance had improved and the number of complaints had fallen steadily.