Danny Fullbrook
BBC News, Bedfordshire
Luton Rising
The expansion plans include a new terminal building for the Bedfordshire-based airport
London Luton Airport will see annual passenger numbers almost double to 32 million by 2043 after the government approved expansion plans.
It comes despite the Planning Inspectorate recommending Transport Secretary Heidi Alexander rejects them over environmental concerns.
Luton Rising, the airport's owners, said the decision could bring "significant economic, employment and social benefits for our town".
However, environmental campaigners said "with climate change worsening, the last thing any of us need is 70,000 more aircraft a year".
BBC/Danny Fullbrook
London Luton Airport's owners believe the expansion scheme will generate 11,000 new jobs
The plans involve building a new terminal, new taxiways and increasing capacity in the existing terminal from its current 18 million passengers a year.
A government source said: "Expansion will deliver huge growth benefits for Luton with thousands of good, new jobs and a cash boost for the local council which owns the airport.
"This is the 14th Development Consent Order approved by this Labour government, demonstrating we will stop at nothing to deliver economic growth and new infrastructure as part of our plan for change."
The decision over expansion had been delayed three times - most recently so newly appointed Alexander could have more time to consider the application.
Paul Kehoe, independent chair of Luton Rising which is owned by Luton Borough Council, said up to 11,000 new jobs would be created, along with "additional annual economic activity of up to £1.5bn" and "up to an additional £13m every year for communities and good causes".
BBC/Janine Machin
The airport wants to increase passenger capacity to 32 million a year
Andrew Lambourne of campaign group LADACAN, which has opposed Luton airport's expansion, said the government had ignored local people.
He said: "The government has said it believes in local decision making, yet has ignored the 90% of residents, groups and councils which strongly opposed this application because they know it is out-of-keeping with the area.
"People living under the flight path are already at risk of health damage from being awoken by night flights, so adding 70% more is inhumane.
"And with climate change worsening, the last thing any of us need is 70,000 more aircraft a year creating greenhouse gases and contrails."
BBC/Janine Machin
Operators at the airport will compete over the new passenger capacity, including Luton-based Easyjet
Marion Geoffroy, managing director of Wizz Air which is the largest operator at the airport, said she hoped the increased capacity would allow the company to grow.
"We are absolutely confident, looking at the trends of the last few years, that there will be enough demand for us to put more capacity in Luton airport," she said.
Operators will be competing for the new space. Earlier this week, Jet2 began to offer routes for the first time, but Ms Geoffroy insisted "competition is good".
"Competition just makes you better. We are delighted the airport can offer more capacity, but we will be competing for sure."