The average cost of renting a property has fallen by more than two per cent during the first three months of the year as "accidental landlords" flood the market, research showed this morning.

Property website Gumtree.com said average rents had dipped by 2.2 per cent across the UK during the first quarter of the year, with Oxford - the worst affected area - seeing a six per cent plunge.

It blamed the falls on the rental market being flooded with properties, as people opted to rent out their home instead of sell it, in the hope that house prices would recover.