House of Commons Library

Heathrow expansion

Published Monday, June 12, 2017

This paper gives an overview of the debate about the expansion of Heathrow Airport. It looks at the work of the Airports Commission and the subsequent decision by the Conservative Government to support a third runway and sixth terminal at the airport; the environmental issues and concerns surrounding the decision; the economic case and how the scheme will be taken forwards.

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In October 2016 the Conservative Government announced that it would support a planning application by Heathrow for a third runway and a sixth terminal, to the north west of the existing site. This is in line with the recommendation of the Airports Commission, which reported in July 2015. Consequently, the Government published for consultation in February 2017 a draft National Policy Statement (NPS) for airports. The draft NPS is subject to parliamentary scrutiny and will require approval by both Houses of Parliament. Once the NPS is approved Heathrow may proceed with a planning application, in the form of a Development Consent Order (DCO).

Expansion at Heathrow is not without controversy. While it enjoys widespread support amongst Conservative, Labour and SNP MPs, it is opposed by the Liberal Democrats and the Greens and by some MPs whose constituencies are overflown by planes flying to and from Heathrow. It has also been opposed by successive mayors of London, from both major parties.

There are longstanding concerns about the environmental impact of expansion, in particular:

  • how the increase in traffic will affect air quality around the airport;
  • whether more flights will cause difficulties for the Government’s climate change obligations; and
  • how noise will impact those living near the airport and under the flight paths

More generally, there is ongoing debate about the robustness of the financial and economic case; whether the taxpayer will be expected to fund surface access improvements; and whether expansion could or should better serve domestic markets. These questions have become more acute following the UK’s decision to leave the European Union.

This paper focuses only on the plans to expand Heathrow. More general information on the airport can be found in our paper SN2893, which covers airports across the South East and London. Information on airports across the rest of the UK can be found in SN323. These and other papers can be found on the Aviation Briefings Page

Commons Briefing papers SN01136

Authors: Louise Butcher; Louise Smith; Elena Ares; Henry Midgley

Topic: Aviation

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