Prime minister David Cameron has admitted Britain is “falling behind” the rest of the world when it comes to infrastructure and called for repairs “to the decades-long degradation of national infrastructure” in the UK.

In a wide-ranging speech on infrastructure, the prime minister also said he wasn’t “blind to the need to increase airport capacity, particularly in the south-east”, but warned progress would be controversial.

Answering critics who have long called for a clearer strategy for growth in the aviation sector, Cameron said the government would bring forward new options, including an examination of the pros and cons of a new airport in the Thames estuary.

Gatwick, he said, was also emerging as a business airport for London, under a new owner, and beginning to compete with Heathrow.

“This affects the competitiveness of every business in the country; it is the invisible thread that ties our prosperity together,” added Cameron.

Business leaders have repeated called for an increase in airport capacity in the south-east, arguing the lack of capacity at London Heathrow is placing a restraint on economic growth.

International Airlines Group chief executive, Willie Walsh, recently branded the government’s position an “unholy mess” and argued it was “going nowhere”.

Speaking at the British Chambers of Commerce’s annual conference in London, he also branded proposals for an estuary airport as “madness”, arguing it would mean the closure of Heathrow.