Prime rents in central London rose for the third consecutive month in May, data from Knight Frank revealed, meaning the half-year change in values was positive for the first time since January 2012.

The 0.2% rise in rental values narrowed the annual decline to 1.4%, while new lettings registrations were 17% higher than 2013 and 48% up on 2012.

Knight Frank highlights that this does not signal a complete upswing in the market, as although half its offices reported an increase, the other half reported flat or falling rents in May.

Tom Bill, head of London residential research at Knight Frank, said: “The data suggests there will be a reversal of fortunes in the prime central London sales and rentals markets in the short to medium term.

“Demand is cooling in the sales market as buyers become wary about high prices and next year’s general election.

“Meanwhile, rental values are rising after a two-and-a-half year decline as the UK economy recovers. Such a switch has happened in previous property cycles in prime central London.”