The Conservative Party has claimed that HMRC inspectors enforcing Labour's incoming "mansion tax" will assess a wide range of home features, including scenic views, conservatories, balconies and large garages, when deciding which properties should be liable for the levy. The claim is based on an HMRC tax manual obtained by the Tories under freedom of information laws, and has prompted accusations from the party that the policy amounts to state "snooping" on homeowners, with ministers having already confirmed that valuation agents can carry out internal inspections of properties.

The high-value council tax surcharge, commonly dubbed the mansion tax, was announced by then-Chancellor Rachel Reeves at last year's Budget and is due to come into effect in 2028, applying to homes worth more than £2million. Alongside features such as conservatories and garages, inspectors will also consider more obvious markers of wealth including swimming pools, tennis courts, stabling, annexes and farmland, with those refusing an inspection facing a fine of up to £200. The Office for Budget Responsibility estimates 165,000 properties will be affected in the first year, rising to 167,000 by 2030, with annual charges ranging from £2,500 to £7,500 depending on value; the Government says the surcharge will apply to fewer than 1% of properties in England.