Can I drive into the LEZ with a foreign Vehicle Registration Plate?

It depends.

A foreign Vehicle Registration Plate holder must also ensure that his or her vehicle meets the conditions of admission to the LEZ. You can verify this easily using this check tool.

If such a vehicle meets the conditions of admission it must be registered once only, in advance. This applies to all types of vehicles: passenger cars, campers, delivery vans and trucks, agricultural vehicles and buses (including coaches).