A proposal to levy an annual £7.5bn tax on London's most valuable homes, championed by Greater Manchester Mayor Andy Burnham as part of a wider devolution and levelling-up settlement, has landed with predictable force in the capital's property market. The plan, understood to target properties above a value threshold in the region of £1.5m, would redirect revenue collected from London's wealthiest boroughs towards housebuilding and infrastructure in the North, Midlands and other underfunded regions. For an industry accustomed to policy churn, this is not simply another tinkering with stamp duty - it is a structural challenge to how London's property wealth is treated relative to the rest of the country, and it deserves serious analysis rather than dismissal.