A third runway could see flights increase from 480,000 a year to more than 700,000. But a BAA spokesman said a third runway "will not go ahead unless strict environmental limits are met" on noise and air quality. Ministers also revealed that planning permission would not be given before the next general election, expected in May 2010. Rebels thought some 30 MPs would defy the Government, not enough to defeat it. Andrew Slaughter, MP for Ealing, Acton and Shepherd's Bush, quit as parliamentary private secretary to Lord Malloch-Brown to vote against the Government.