if you put a windfall tax on the energy companies, what that means is that you discourage them from making the investments that we want to see, that will, in the end, keep energy prices lower for everybody. but with the cost of living a key issue in the run up to this week s local elections, the idea of a windfall tax has also been picked up by the snp and the liberal democrats. families and pensioners are really struggling to pay their heating bills, their energy bills, their motoring costs. and we need them to have a tax cut. the liberal democrats are arguing for a vat tax cut worth £600 for the average family, and one of the ways we would fund that is through a windfall tax on the oil and gas companies. bp, meanwhile, has promised to invest £18 billion on what it calls low emission oil and gas projects in the north sea, as well as on expanding offshore wind power. it says this will boost energy security, as well as meeting