The Department of Transport is responsible for the security of UK airports. Their policies are implemented at each airport by the airport security staff. Airlines and travel companies do not set these rules.
Before flying, you will go through the airport security area. These measures are in place to help maintain your safety, so familiarisation with the rules will help you pass through the security checks as quickly as possible. Restrictions on what you can take on board varies from time to time, so we recommend you read the latest security advice on the Department of Transport web site before every flight from the UK.
Please remember that security procedures can also vary from airport to airport. More information can be found on the web site of the airport you are flying from, and usually from that of your airline or travel company.