London City Airport will open two temporary security lanes on February 27.
Speaking exclusively to ABTN at the Business Travel and Meetings Show in London, the airport's chief operating officer said the extra lanes would alleviate the long queues endured by passengers since security was tightened at Christmas.
Darren Grover said a restaurant and bar in the departure lounge will be closed to accommodate the new facilities which will increase capacity by 50%.
He admitted to being "extremely concerned" by recent events at the airport which have led to a number of complaints from airline passengers.
"The security area currently has four lanes. It has been a little on the small side, but we've always known that," he said.
"The change in security measures has meant the screening time is longer. But what has really hurt us is the number of trays used by passengers passing through security has increased by 78% year-on-year."
Government regulations require airports to check a certain percentage of hand luggage.
"It means the average traveller has gone from using an average of one-and-a-half trays to almost three."
Grover had already moved to deal with congestion at the airport by recently announcing an £8 million project to create a new first floor with expanded security lanes. Work is scheduled to finish in October.
But he said the airport had been "caught out" by recent events and was know investing heavily in temporary solutions to rectify the situation.
He said: "I'd like to go on the record as saying that we apologise to our customers and we realise that the situation has been totally unacceptable. We are doing everything we can to improve the experience as our USP [unique selling point] has always been our slick procedures - we haven't had any similar problem in 21 years."
Grover said the company would be spending in the region of half a million pounds on the temporary security lanes.
He said extra staff were working everyday and that he had also taken on temporary customer service workers to assist queues in the airport.
Grover also denied that irregular services on the DLR [Docklands Light Railway] were to blame for the long queues at the airport.
"There were instances were three train would arrive within minutes of each other and suddenly 250 people would arrive at security. It is impossible to process that many people in five minutes. But the DLR has some issues with the closure of Bank station which have now been resolved."