Passengers will be turned away at checkpoints if they arrive less than 35 minutes before their flightsBritish Airways passengers will be turned away at security checkpoints if they arrive less than 35 minutes before their flights under a strict regime at Heathrow's new terminal, which is opened officially today by the Queen. Passengers will no longer be given the chance to run for the gate but will be redirected to a BA desk where they will have to rebook. They may have to pay hundreds of pounds for new flights. BA said the change was being introduced to prevent one late-running passenger from delaying up to 350 other people on a flight. The 35-minute rule is expected to be introduced gradually at other Heathrow terminals and other airports. The rapid growth in passengers checking in online the night before they fly is resulting in more people arriving late at the airport. The 'BA terminal' BA is moving 92 per cent of its 550 daily flights to the £4.3 billion Terminal 5, which will cater for 30 million passengers a year from March 27. Today's opening ceremony of the biggest free-standing building in Britain marks the start of a new era for the airport. The gleaming, glass-encased structure built on a former sewage works between the runways, is finally complete more than 20 years after the first plans were drawn up. Check-in should be much faster than at other terminals because there will 96 self-service kiosks and a similar number of fast bag-drop points, in addition to 54 staffed check-in desks. There will be 660 security staff manning 20 security screening points, each equipped with the latest rapid scanning machines. But the benefits of faster check-in and security will simply allow passengers to spend more time in the departures lounge, where BAA, the airport's owner, hopes they will spend more in shops and restaurants. BA said it would no longer allow passengers to "have a go" at making a flight if they arrived late at the airport. Traditionally, passengers have been told that, if they run, they might get to the departure gate before it closed. But the new regime will force everyone to spend at least half an hour in the departure lounge. Their boarding passes will be scanned as they queue for security checks. Those whose flights are departing in less than 35 minutes will be refused entry to the "airside" area. David Noyes, BA's director of customer service, said: "The problem with not having a cut-off point for going through security is that one person cutting it fine can delay a whole flight. It's an excellent service for one person but poor service for the hundreds already on board." Online check-in Almost a third of BA passengers already check in for their flights online and therefore do not have to comply with the airline's minimum airport check-in time of 45 minutes before the scheduled departure. BA said that some people on business trips checked in online but then failed to turn up at the airport and did not cancel their seats because they knew they would still get a refund. A spokesman said: "We can be waiting for a passenger who may not even be at the airport. Under the new system, we will know whether they have passed through security and we will have more on-time departures." BA will continue to recommend that passengers arrive at the airport two hours before their flights. BAA admitted yesterday that Terminal 5 was not yet fully completed. Ten of the 250 lifts and escalators were not working and other systems would need "a bedding-down period". More than 15,000 volunteers have taken part in several trials but this number is far fewer than the 70,000 passengers that the terminal will handle every day. Andrew Wolstenholme, BAA's capital projects director, said: "In order to test it we need the building to be at full load. And we won't get that full load until we get through a hot summer and cold winter." About a fifth of Terminal 5 passengers will have to catch buses from the departure gates to their aircraft. BAA admitted that some passengers were likely to go to the wrong terminal and could miss their flights. Some BA flights move to Terminal 5 on March 27 and others on April 30. Another 54 airlines will be moving terminals after Terminal 5 opens. The Queen's visit comes more than 50 years after she opened the airport's first passenger terminal in 1955. All the other terminals due to be rebuilt or upgraded over the next five years. Sir Nigel Rudd, BAA chairman, said: "It is by any standard a triumph of ambition, commitment and collaboration. It will breathe new life into Heathrow, allowing us to continue our transformation of the rest of the airport and will put Heathrow and BAA back where they belong."