CONTROVERSIAL speed cameras dubbed "yellow vultures" have been erected to pick off motorists going too quickly through roadworks due to start next weekend on a busy stretch of the M27.

Perched like birds of prey on limbs extending above the road, the cameras will catch any motorist whose average speed tops 50mph through a section of road widening works, starting on Saturday.

The Highways Agency claims that the cameras are needed for the safety of the workers.

However, motoring groups warn that they could make the road less safe and have branded them a nuisance at night.

The cameras will be in place for up to 15 months while the Highways Agency carries out a £36m project to ease congestion by building fourth lanes between junction three at Nursling and junction four at the M3.

It says that drivers can expect "slight delays" of up to ten minutes.

Motorists are already feeling the frustration of lengthy delays from a smaller £18m project to add climbing lanes between junctions 11 for Fareham and 12 for Portsmouth.

The Association of British Drivers says that while it does not object to speed limit enforcement, the "yellow vultures" could cause some drivers to overcompensate by slowing too much when approaching a second camera. It also feels that the cameras could distract drivers from the road by encouraging them to keep a constant eye on their speedometer.

A Highways Agency spokeswoman refused to say when the cameras would operate, or why "yellow vultures" would be used.

She said: "We use safety cameras, including average speed cameras, to enforce speed limits at roadworks where road speeds are lowered and drivers are likely to speed.

"Essentially the cameras are used to protect the workforce, motorists and keep traffic moving through the roadworks."

She added that the cameras had been installed and operated in accordance with Department for Transport rules and guidance from the safety camera partnership.

Roads bosses are optimistic that the major roadworks can be finished by Christmas.