Bury Council has already threatened action over motorway adverts

It said on Monday there was a danger of drivers getting distracted by the signs while travelling at high speeds.

Local authorities are being encouraged to take action against landowners displaying adverts close to motorways.

The Highways Agency said its campaign was being supported by police forces across the region.

Agency divisional director for the north, Arthur Ashburner, said: "These illegal signs in fields have spread the length and breadth of the motorway network in the North West and pose a serious threat to road safety because they can be a distraction to drivers.

There is also an issue about their poor appearance and how they spoil the open countryside John Byrne, Bury Council

"It only takes a driver to be distracted for a moment travelling at 70 miles per hour on the motorway and there could be a serious accident causing injury or death.

"We have been monitoring closely the proliferation of these signs... and will now be working with local authorities in the region to get them removed."

Bury Council has already written to landowners outlining the law and the fact that they intended to take legal action unless the advertising was removed.

Councillor John Byrne, executive member for environment and transport, said: "Bury Council takes seriously the road safety issues that arises from these unauthorised advertisements.

"There is also an issue about their poor appearance and how they spoil the open countryside in which they are located."