Damian Green, the immigration minister, said as many as 80 people, most of them currently working as office staff, will be reassigned to Heathrow through the summer, The Daily Telegraph reported. London is hosting the Summer Olympics and expecting thousands of additional visitors.
Green made the announcement after Prime Minister David Cameron called the lines at Heathrow "unacceptable."
Most of the additional staff will function as part of a so-called hit squad, to be deployed as needed, Green said.
"The problem is that people, at certain times, on certain days, have to wait too long," he said. "We're addressing that problem.
Mark Serwotka, the general secretary of the Public and Commercial Services Union, was dubious.
"Drafting in staff from other areas of an already overstretched agency is like putting a sticking plaster on a serious injury, it will do nothing to stop the inevitable from happening," he said.
Willie Walsh, chief executive of International Airline Group, the parent company of British Airways, complains that travelers have had to wait as long as 2 1/2 hours.
"The Government has tried to convince people that we don't have a crisis," Walsh said. "The Government is misleading people. We have a crisis, it has been there for some time and we need urgent action."