The couple's move, earning them at least pounds 200,000 free of tax, follows a price surge which has seen the value of properties in some parts of London and the south-east of England rising by more than 50 per cent in the past 15 months.
Jeremy Leaf, a housing market spokesman for the Royal Institution of Chartered Surveyors, which represente estate agents, warns against applying the Islington experience too closely to other parts of the country. Prices, he says, may not rise so swiftly in future - but there is no immediate risk of an 80s-style collapse either.
"A lot depends on any Government measures taken to curb gazumping or to increase stamp duty. Issues like this, including interest rate rises or the abolition of mortgage interest relief, can affect confidence. One does wonder why Mr Blair is selling before the Budget."
Amanda Davidson, a partner in London financial advice firm Holden Meehan, says: "My advice would be to put the maximum into Premium Bonds. If they use their children's entitlements, they can invest up to pounds 100,000. There is always the chance to strike it lucky and, as we know, Mr Blair is lucky."Reuse content