Sainsbury’s has begun a huge promotional push in an effort to lure cash-strapped shoppers into its stores and to its web site.

Last week the grocer launched thousands of buy-one-get-one-free offers in store and online, as well as price cuts, which will last until May 20.

It began the value drive with a TV push over last weekend’s bank holiday. All five ads, for Tu Clothing, Sony TVs and groceries such as lamb chops, focused on discounting.

A Sainsbury’s spokeswoman said: “It was a bigger campaign than usual on the bank holiday.” On its web site, Sainsbury’s said: “This week, we’ve put together a selection of our very best deals.”

Pali International analyst Nick Bubb said the price-push was “a sign of the times” in the face of the credit crunch and consumer slowdown.

Some City analysts believe the initiative could be a response to rival Tesco’s renewed price campaign launched this spring, but all the big grocers are increasingly asserting their price and value credentials.Even Harrods has given 10,000 reward-card holders a 20 per cent discount, in a sign that even the well off may be less willing to spend.

According to TNS Worldpanel, Sainsbury’s sales growth has fallen behind its big three rivals in the 12 weeks to April 20.

Sainsbury’s till roll sales rose 4.2 per cent, compared with Morrisons’ 9.2 per cent, Asda’s 6.8 per cent and Tesco’s 4.5 per cent. Overall, Sainsbury’s market share fell from 16.4 per cent to 16 per cent in the period.

Exane BNP Paribas analyst Tim Attenborough said: “They have had a marvellous three years but need to regain momentum.”

On Wednesday, Sainsbury’s will post its preliminary results. Analysts expect it to report pre-tax profits of£485 million, against£380 million for the previous 12 months.