The expansion of Heathrow Airport has involved several proposals by Heathrow Airport Holdings and an independent proposal by Heathrow Hub, to increase capacity at Heathrow Airport.
In December 2006 the Department for Transport published a progress report on the strategy which confirmed the original vision of expanding the runways. In November 2007 the government started a public consultation on its proposal for a slightly shorter third runway (2,000 metres (2,187 yd)) and a new passenger terminal.
The plan was supported by businesses, the aviation industry, the British Chambers of Commerce, the Confederation of British Industry, the Trades Union Congress and the then Labour government. It was opposed by Conservative and Liberal Democrat parties as opposition parties and then as a coalition government. Boris Johnson, the past Mayor of London, as well as many environmental and local advocacy groups and prominent individuals also opposed the project. While the expansion was originally cancelled on 12 May 2010 by the new coalition government, as of 1 July 2015 the plan has been suggested as the best option by the Airport Commission. On 25 October 2016 a new northwest runway and terminal was approved by the Government. It was opposed by Zac Goldsmith, who resigned as Conservative MP for Richmond Park in protest, and stood in the resulting by-election as an anti-Heathrow expansion candidate. Goldsmith failed to win re-election at the by-election.
In January 2009, the then Transport Secretary Geoff Hoon announced that the UK government supported the expansion of Heathrow by building a third runway (2200m) and sixth terminal building. The government would not undertake construction, but encourage the airport operator (BAA) to apply for planning permission and carry out the work. The government anticipated that the new runway would be operational in 2015 or soon after. In 2009 the government declared that they did not intend that the third runway should be used at full capacity when it is first opened. Initially the extra flights should be limited to 125,000 a year until 2020, rather than the 222,000 at full capacity.