Sales were also distorted by Easter falling in different months between 2008 and 2010, making comparisons difficult.
Total sales fell 0.2% compared to April 2010.
Sales over the past three months, which cancels out the distortion of Easter timings, saw like-for-like sales up by 1.6% on April 2009 and by 3.8% overall.
Non-food sales were down 2.1% like for like and 4.4% overall as consumers stuck to essential purchases over discretionary items as uncertainty over the election affected consumer confidence.
Non-store sales, which include internet, catalogue and phone sales, were 15.8% up on April last year in line with growth in previous months.
Stephen Robertson, British Retail Consortium director general, says: “There’s no question customers are more willing to spend than 12 months ago but still nervous. People need to know how a new Government’s moves to tackle the deficit will affect their incomes and jobs. Even if the measures are tough, knowing what they are could be better than the current uncertainty.”