According to the British Retail Consortium (BRC), the U.K. shop prices declined by 1.7% year-on-year in April, after a 1.7% decline in March.

The decline was mainly driven by a drop in non-food prices, which plunged 2.9% year-on-year in April.

Food prices rose at an annual rate of 0.1% in April.

"The thirty-six consecutive months of price falls is being driven by intense competition across the industry. It has knock on implications for margins and profitability given the combination of continued investment in digital and rising cost pressures, compounded by recent policy announcements," BRC Chief Executive, Helen Dickinson, said.