Thames Water will be slapped with a fine for causing traffic “mayhem” in a Wiltshire town by mistakenly installing temporary traffic lights.

The utilities company erected temporary traffic signals on the A4 London Road, between the Roebuck pub and St Margaret's Mead in Marlborough, on the weekend of Saturday, May 20.

But despite causing significant disruption to motorists in the town, the traffic lights remained unmanned, and no work was carried out at the site.

This sparked an investigation by highways officers for Wiltshire Council, who soon ordered Thames Water to remove the lights after discovering they had been “put up in error".

The council have now confirmed it will be issuing a fine as punishment for the mistake.

The Wiltshire Gazette and Herald: The A4, London Road, in MarlboroughThe A4, London Road, in Marlborough (Image: Google Maps)

Cllr Caroline Thomas, cabinet member for transport and the councillor for Marlborough East, said: “I brought the issue of unmanned traffic lights where no work was taking place to the attention of highways officers, given the significant disruption caused.

“Their investigation identified that the temporary lights had been put up in error, and Thames Water was instructed to remove them. We will be issuing Thames Water with a fine to reinforce the need for them to take greater care in their operations.”

Town councillor Kym-Marie Cleasby, who raised the issue at a town council planning meeting, said the costly error had caused “misery” for road users in Marlborough.

She said: “It caused mayhem for well over a day because the road was closed but nothing seemed to be going on, it was impacting people in a big, big way.

“Any road in Marlborough that gets roadworks put in has a knock-on effect throughout the entire town.

“For anybody doing business, going to school, or just going about their daily life, it becomes a misery. Mistakes do happen but that did seem to be a rather odd one.”

She added that it was her understanding the lights had been put in place as a result of a three-year-old works order.

The revelation comes after Thames Water were fined for issues with some of their temporary signals in Swindon.

Thames Water claimed that they did not have any record of any works taking place in the London Road area at that time.

A spokesperson said: “We aim to take a collaborative approach with the local authority when arranging planned and urgent repair work, to minimise disruption to residents and businesses.

“Our customers are at the heart of what we do and we are sorry if we cause inconvenience during specific work.”