Part of the M20 will shut tonight as Operation Brock returns ahead of the summer holidays. The contraflow scheme, which sees lorries heading to the continent queue on the coastbound side between Junction 8 for Leeds Castle and 9 for Ashford, will be redeployed overnight. It means the motorway will be out of action from 8pm until 6am tomorrow from Junction 9 to 8 London-bound and Junction 7 to 9 coastbound. The Brock system sees the London-bound carriageway operate as a contraflow with narrow lanes and a 50mph limit and is expected to remain in place throughout the summer holidays. It comes as …