New research by Gatehouse Bank has revealed that Winchester is home to the most vulnerable rental market as tax changes amplify the threats to landlords.

Tax changes in recent years – including the introduction of the extra 3% surcharge on second homes and the phasing out of mortgage interest tax relief – have curbed the buy-to-let market, leading to an environment in which yield is no longer king. Landlords can no longer consider yield alone, they must also take account of a range of local factors to protect their returns.

The findings from Gatehouse Bank found that the most exposed landlords are in Winchester - the ancient capital of England - where available rental properties have sat empty for 248 days, rents are over half of average earningsand yields are half those of top towns and cities.

Other locations where gains were hard to come by areCambridge, Chichester, Warwick and Reading, while landlords are also vulnerable in Woking, Watford, Chelmsford, Oxford and Guildford.

The Bank’s study took into account the second tier of economic indicators, including how long available rentals have been on the market, as well as the affordability ratio between average salaries and rents, in contrast to studies which concentrate solely on yield.

Based on yield alone, Padstow, Bedford, Taunton, Shrewsbury and Salisbury would make up the least attractive buy-to-let hunting grounds.