Tesco and Morrisons continued to feel the pressure in the last three months as only the discounters and Waitrose grew ahead of the UK retail market.

For the 12 weeks ending 13 May, Sainsbury's held on to its share of the market while Tesco and Morrisons grew 1.9% and 1.2% growth respectively, according to the latest market share figures released by Kantar Worldpanel.

This, however, compared to growth of 25.4% from Aldi to achieve a share of 2.8%, while Lidl held on to its record 2.8% share from last period with 11.3% growth. Waitrose continues to outpace the market with 7% growth.

"The ongoing strong performances of Aldi and Lidl have led some commentators to believe that consumers are deserting conventional stores for the discount sector," said Kantar Worldpanel director Edward Garner.

"However, a more realistic picture of shopper behaviour shows that many consumers are continuing to do their main shopping trip in their usual store, but spending the remainder of their household budget on the discounters."

The market as a whole grew by 3.1% - a "sharp" decrease on the 5% growth reported last period, the researchers reported. In the last four weeks of this period, the market declined by 1%.

Kantar said while the declines may appear "alarming", there are "exceptional factors".

"Easter and the Royal Wedding helped year-on-year growth soar to a remarkable 7.6% in the four weeks leading up to May 15 2011 - a hint of what's to come over the Jubilee weekend," said Kantar Worldpanel director Edward Garner. "Comparing the current figures with the same period two years ago, the four week growth stands at 6.5%. This is actually in line with long-term trends and shows 2011 as the anomaly."

According to the Kantar data, grocery inflation was 5.1% in the period - a decrease from the level of 5.5% last period but above the market growth.