A 50mph speed limit has been introduced on a long stretch of the M20 - and will stay in place until 2020.

The new restriction is being enforced in both directions by average speed cameras which will monitor vehicles between junctions 9 for Ashford and 11 for Hythe.

The limit came into force today as building work continues for the long-awaited junction 10a.

Later today, the London-bound carriageway will be closed between junctions 9 and 11 between 8pm and 6am.

And tomorrow the coastbound side will not be in use through the same time that evening.

A Highways England spokesman said: "Work to improve the network continues this week on the M20.

"Today there will be a full westbound closure between junction 9 and 11 overnight between 8pm and 6am.

"A clearly signed diversion will be in place via the A20 and A292.

"Tomorrow there will be a full eastbound closure between junction 9 and 11 overnight between 8pm and 6am.

"A clearly signed diversion will be in place via the A292 and A20.

"In addition, from 6am today there will be a 24 hour lane closure and 50mph speed restriction in place in both directions between junctions 9 and 11.

"This will remain in place until January 2020."

The £104 million junction 10a project was given the go ahead in December.

It will see a new roundabout built over the motorway, just 700 metres away from the current junction 10 and close to the Pilgrims Hospice.

Elsewhere, resurfacing work will take place between junction 4 of the M20 to junction 2a of the M26, westbound for five nights from 10pm until 6am.

A diversion will be in place via the A20.

Drivers are also being told to expect disruption between junctions 3 and 5 of the M20 for smart motorway works.

From today lanes one and two will be closed in both directions for five nights between 9pm and 6am.