Vine Weevil & Privet

If it is vine weevil, then get yourself some Provado to water into the soil to kill the grubs before they hatch out again this year. You can water it on as soon as the soil warms up which is usually abiut April time

There is a privet weevil that is smaller than the vine weevil and they have been found in the south of England. This site has a photo of leaves damaged by the insect.

http://www.rhs.org.uk/Advice/profiles0301/privet_weevil.asp

Very unlikely that your hedge is suffering from vine weevil - it wouldn't survive two years and you would find lots of big fat grubs around the none-existent roots if it was! Fourseasons suggests the most likely culprit.

As for treatment the best thing is to dig up your plants, excavate your trench clear, set old soil aside and check it for grubs using sieve reuse later at leisure. Meanwhile hose down the roots until they are bare before replanting them in new compost in the cleaned trench. Anything less means a recurring problem. Hope your hedge is short one!