Essential work to fix a leak on an underground gas pipe that sits directly beneath the A590 starts on Monday.

A plan has been agreed that will keep the A590 open throughout the four days of work, with traffic lights controlling the flow.

Cadent, which manages the North West’s gas mains, carried out two overnight investigations, to pinpoint the source of the leak on the main.

It now knows the gas is coming from a four-inch diameter metallic main, near the junction of the A590 and Park Road, at Swarthmoor.

Cadent has liaised with Highways England, which owns this trunk road, to schedule the work to start after the morning rush-hour on Monday.

“We know this is not ideal, but it is work that needs to be done to ensure public safety and keep a reliable supply of gas to local homes,” said a Cadent spokesman.

“While the leak is not at levels that need worry people – we’ve contained it and it’s being regularly monitored – we have to go in and fix it, before it gets any worse.

“So, we have worked closely with Highways England and agreed that we will start work after the morning rush-hour on Monday.

"Our lights will be manned from 8am to 8pm and will operate automatically at all other times.”

Gas supplies locally should not be affected.

The spokesman added: “If anyone smells gas while the work is taking place, or at any time, ring 0800 111 999 immediately. The smell may be unconnected to our work, and we would want to send an engineer to check and be absolutely sure.”

Cadent manages a network of more than 80,000 miles of mostly underground pipes that ensure gas reaches more than 11 million customers. This makes it the biggest of the UK’s four gas distribution networks.