Sarah Olney

The debate surrounding a third runway at Heathrow has stretched over the past three decades. The Liberal Democrats have long stood by communities who oppose a third runway, arguing that the economic benefits are overstated and the environmental consequences are unavoidable. Although I have always opposed a third runway at Heathrow, the current proposal could not have come at a worse time. The cost of expansion has doubled over the past 10 years, and the addition of nearly 300,000 more flights, which expansion implies, will make our net zero targets almost unachievable. It is widely rumoured that even Heathrow Airport Ltd did not believe the timing of expansion to be practical. Despite that, on 29 January 2025, the Chancellor announced her support for a third runway to be built at Heathrow airport. This endorsement was the landmark announcement during her speech on growth; as such, it has a significant amount of political weight behind it. My plea to the Minister is that any decision taken on a third runway at Heathrow should be based on merit and unbiased data, not politics. The decision has an enormous impact on millions of lives, and it must be more than just a signal to investors to compensate for the Government’s economic mismanagement. The Chancellor believes that expansion at Heathrow will produce economic growth. Nearly 18 months later, however, the Government have yet to produce their economic analysis to support that assertion, and the figures raised in the Chancellor’s speech on growth were drawn directly from an internal business case prepared for Heathrow airport and have not been independently verified. The Department for Transport’s own updated appraisal report from 2017 shows that the net present value of a third runway ranges from just £3.3 billion to minus £2.2 billion. Now it has been admitted that even that figure is a generous estimate, as the DFT’s guidance suggests that international transfer passengers, who are estimated to make up 75% of a projected third runway’s capacity, do not contribute to the UK’s economy. When discounting those passengers, it is estimated that the net present value could be reduced by as much as a further £5.5 billion. In addition, the New Economics Foundation asserts that twice as many people fly out of the UK than fly in, thus exporting more money out of our economy. An assessment of the impacts of inbound and outbound tourism flows is currently missing from the economic analysis of aviation’s contribution to the economy. Will the Minister provide reassurance that that research will be conducted and published with the airports national policy statement? Heathrow Airport Ltd has cited that the cost of building a third runway will be an eyewatering £49 billion, before factoring in an estimated £100 billion in carbon abatement costs and at least £15 billion of investment on surface access upgrade improvements. Without that upgrade, there will be no way to deliver sufficient passengers to Heathrow to utilise the additional capacity and deliver the supposed economic benefits. The Government have said that funding for a third runway at Heathrow will be privately financed. With Heathrow already drowning in over £15 billion-worth of debt, I am not convinced. I would therefore like to ask again, will the Minister provide reassurances that none of the costs associated with building a third runway at Heathrow will be pushed on to the taxpayer?