The new rules were introduced after the arrest of 21 people in connection with a terror plot to blow up as many as 10 aircraft.
Increased security measures have resulted in huge queues and cancelled flights all over England.
Under the new restrictions, passengers may only take the following items into the cabin in a, preferably transparent, plastic bag:
- Pocket-size wallets and pocket-size purses plus contents (for example money, credit cards, identity cards, etc – handbags are not allowed)
- Travel documents essential for the journey (eg passports and travel tickets)
- Prescription medicines and medical items sufficient and essential for the flight (eg diabetic kit), except in liquid form unless verified as authentic
- Spectacles and sunglasses, without cases
- Contact lens holders, without bottles of solution
- For those travelling with an infant: baby food, milk (the contents of each bottle must be tasted by the accompanying passenger) and sanitary items sufficient and essential for the flight (nappies, wipes, creams and nappy disposal bags)
- Female sanitary items sufficient and essential for the flight, if unboxed (eg tampons, pads, towels and wipes)
- Tissues (unboxed) and/or handkerchiefs
- Keys (but not with electrical key fobs)
British Airways was advising passengers not to travel unless it was essential.
"Any customers who do not need to travel today are advised to stay at home," the company said in a statement.
"Customers who have to travel are advised to check on ba.com where they will be able to find the very latest up-to-the-minute information regarding every British Airways flight."