The tourism industry has welcomed the government's decision to green light construction of a third runway at Heathrow Airport in London, as well as plans for a new high-speed rail link.

VisitBritain, the national tourism agency, said that the announcement was "a very positive decision for Britain's tourism industry," while UKinbound said that the expansion of Heathrow was vital to the country. Additional terminal facilities will also be built at the airport as part of the proposals, which transport secretary Geoff Hoon announced had met the government's environmental criteria imposed as a condition of any expansion project.

The proposed expansion of Heathrow, which is operated by BAA, is an attempt to relieve the strain on Britain's busiest airport. Supporters of the scheme have said that the existing two runways are operating at 99 per cent capacity, and that a third runway is now necessary. Executive chair of VisitBritain, Christopher Rodrigues, said: "Tourism means jobs and this is a very positive for Britain’s tourism industry. St Pancras and Terminal 5 have shown how valuable it is to get the right infrastructure for domestic and international travel.

"These proposals will make Britain’s fifth biggest industry – tourism – even more competitive and offer all tourists better access to the whole of Britain." However, Rodrigues pointed out the importance of making any expansions environmentally friendly. “New infrastructure must be built, but it must be built responsibly. The tourism industry is committed to continuing its investments to reduce its carbon footprint.

“In a resource constrained world, 21st century tourism has to be responsible. We fully support the government’s commitment that a third runway must meet strict environmental standards.” Mary Rance, chief executive of UKinbound, added that the decision would make the UK more attractive to tourists:

"Heathrow has been handling many more passengers that it was designed for, and unfortunately the quality of service for passengers, and in particular, the welcome for inbound visitors has suffered," she said. "As a major international hub and a gateway into the UK and Europe, Heathrow's development is vital to safeguarding the many jobs and other economic benefits that it brings."

BAA's chief executive, Colin Matthews, also welcomed the decision. He said: "This decision opens the door to Heathrow becoming a truly world-class hub airport, and to the UK, maintaining the direct connections to the rest of the world on which our prosperity depends." A new high-speed rail-link between London and Birmingham will also be introduced as part of the planned transport improvements, which could link with Heathrow and Crossrail through a new international interchange.

Richard Lambert, the director-general of the Confederation of British Industry (CBI), said: "This approach to expanding Heathrow's capacity makes real sense. It will create the integrated transport system necessary for an economy that needs to grow in an environmentally sustainable fashion. "Linking Heathrow to a high-speed rail network will increase the proportion of passengers who arrive by public transport and vastly improve connections to London and the rest of the UK."

However, the government's plans have been met with condemnation by the shadow transport secretary, Theresa Villiers, arguing that it would be an "environmental disaster". Villiers said: "Gordon Brown is deaf to the concerns of his own party and millions of people living under the flight path.

"It is a bleak day for Labour's environmental credentials and for many Labour MPs who have spoken out against the foolish approach to airport expansion." Boris Johnson, the mayor of London, has said that he will support a legal challenge against the proposals and challenged Gordon Brown to defend the decision.

"No amount of sweeteners in the shape of transport infrastructure will fundamentally alter the fact that the government is hell-bent on exacerbating a planning error of the 1940s," said the mayor. "I am deeply concerned that the proper processes of coming to this decision may not have been followed, and will support a legal challenge should this prove to be the case."

The London Assembly has also voiced its disapproval over the government's plans. Chair of the assembly's environment committee, Darren Johnson, said: "Expanding Heathrow is a massive mistake. "The London Assembly has carefully considered the evidence from interest groups and individuals, and we remain unconvinced that the expansion of Heathrow is essential to the well-being of London and the wider UK economy."

Geraldine Nicholson, chair of the No Third Runway Action Group (NoTRAG), added: "The government has not listened to the views of the people. Once again it is siding with big business. Our support has come from all quarters and continues to grow every day."