Thousands of residents have been left in the dark because of a council blunder that could cost taxpayers £100,000.

Town hall bosses at East Sussex County Council spent months installing new sensors on more than 3,000 streetlights as a way to save cash.

But officials have been left red-faced after they discovered their hi-tech devices were not turning on at the correct time, and failed to recognise the clocks going forward and back.

Now 3,300 sensors installed over the summer in Newhaven, Seaford, Peacehaven and Telscombe will need to be replaced at a cost of around £30 each.

Peacehaven resident Vicci Baker, 58, said her husband, 62, fell from the front step of their home in Fox Hill after stepping out into pitch blackness at around 6am.

But when she complained to the council she was told to “use a torch”.

Councillor Carl Maynard, the council cabinet member responsible for streetlights, admitted the blunder was “disappointing”.

He said: “Unfortunately all the sensors will need to be taken out and new ones put in. We’d like to apologise to residents for this mistake. We don’t know where the fault lies yet but we are in amicable discussions with our contractor.

“We will be replacing all affected units and resolving the problem within the next six months.”

When asked whether the contractor, Crawley-based company Colas, would be forced to shoulder the cost of the replacement sensors, Coun Maynard said: “We don’t yet know whether the contract was written in that way.”

In order to save money, the council installed the sensors to automatically switch off streetlights in residential areas from 12.30am to 5.30am.

But as the days shortened, people began to complain they were going to work in the dark.

Council employees then realised the sensors would only work on Greenwich Mean Time and were turning on the lights an hour late.

When the clocks go back on Sunday, the sensors will work correctly – but all 3,300 will need to be replaced before British Summer Time returns in March.

Mrs Baker said her husband took a tumble on Monday morning as he stepped out into the darkness.

She said: “I rang the council but they told me nothing was wrong. One person even told me it was fine and I should use a torch.

“Another officer told me people don’t get up for work that early so it didn’t matter – but firemen, milkmen and postmen do.

“People could be murdered or raped in the darkness because of this stupidity. It’s completely ridiculous and the buck stops at the council.”

Councillor David Tutt, leader of the Liberal Democrat group on the county council, said there appeared to have been “a major error”.

He said: “It would be funny if it wasn’t so expensive. Someone has got to be held accountable for this.

“I will be asking serious questions of Carl Maynard and I just hope the contract was written in a way that protected the taxpayer from these costs.”