Expanding Heathrow and Gatwick is "crucial" for this government after years of people sticking "their heads in the sand" over plans for new runways at south east airports, the Secretary of State for Transport said.

Heidi Alexander made the remarks as she outlined its vision to "modernise" the aviation sector at the annual AirportsUK dinner at a time when passenger levels at the country's airports had grown by 7 per cent – and signs indicating 2025 would be a record breaking year.

She said: "It's clear this is a trend, not an unusual year. In fact, everything points to a record-breaking 2025 – and it's easy to see why.

"The world has never been more interconnected. The desire for travel never stronger. 

"Global forecasts show a near doubling of passengers and cargo in the next 20 years  

So the demand is there. It's growing. And if we don't seize it, we not only risk being outpaced by European competitors, but we will be on the wrong side of public aspirations."

The Government has already announced its support for a third runway at Heathrow Airport – which has put in £2.3billion to overhaul its infrastructure – and more recently said it was 'minded to approve" a second at Gatwick.

She added: "We see airports as a crucial pillar of our plan for change. And it's why we've acted, and acted quickly, across three areas – starting with expansion. 

"It's no secret that long ignored capacity issues in the south-east, has meant some of our major airports are now bursting at the seams.

"And yet – when it came to expansion – too many people stuck their heads in the sand. It left the industry in a perpetual holding pattern, with decisions circling around Whitehall for years, waiting for a clear signal."

Expansion at Heathrow would be the first new full-length runway in the country for quarter of a century with the transport secretary saying her job was now to balance "economic benefits of expansion with social and environmental commitments."

She said this was reflected in her caveated support for Gatwick – with a "clear path for expansion" set out if certain conditions are met.

A final decision on whether to approve Gatwick's expansion is expected to be made on October 27.

The transport secretary finished: "I will never accept the false trade off that pits growing aviation against protecting our environment.

"I honestly believe we can, and must, do both. And how we do that is already being answered…

"Firstly, we cannot hope for quieter, cleaner and greener flights if our most critical piece of infrastructure is stuck in the past.

"We must ramp up work on reducing emissions. Green flight isn't only essential for the industry, it's existential."