Jason Gordon, retail expert at Booz & Co, a leading consultancy, said: "From the retailers I've been speaking to, I expect prices to increase by between 5 per cent and 8 per cent. The majority of retailers will 'round up' rather than 'round down'. There have been so many years of price deflation, retailers need to move up prices to stay profitable. The pressure to increase prices has been building for some time, and that time has come now."