Heathrow Airport warned that its planned third runway could open around 2039, four years later than the government’s 2035 target, after saying the original timetable was increasingly difficult without planning reforms. The airport hopes to secure planning permission by 2029 and open the runway within a decade, as part of a wider £49 billion modernization. Prime Minister Andy Burnham declined to say whether he supports the project, arguing that Londoners’ views should be heard first. Burnham opposed the runway while Mayor of Greater Manchester but later said he was open-minded about it. The expansion is estimated to cost £33 billion, could raise Heathrow’s annual flight cap from 480,000 to 720,000 and is projected to create about 100,000 jobs, although Heathrow has cited a higher figure. Environmental groups, local residents and Mayor of London Sadiq Khan oppose the project, while Heathrow, Unite and the GMB support it.