Asda will start to cut another 5,000 prices this weekend and has pledged to provide customers with "absolute" price transparency.
By Easter, the grocer said it will have cut a total of 12,500 prices this year.
Asda vowed to demonstrate value to shoppers by bidding "goodbye to bogofs and any deals or promotions that aren't substantiated by a price".
The retailer said it will not "baffle" consumers by making "vague claims or putting up any prices that can't be fully justified".
It promised: "Customers are guaranteed to be always shown the price they'll pay for every item, deal or no deal."
Asda chief merchandising officer Darren Blackhurst warned suppliers that the grocer would "not stand for any price rises that can't be justified".
He said: "With the country in recession we need to do all we can to lower the cost of the weekly shop and do the right thing by our customers. That's what our price pledge is all about – good honest value week in, week out."
Asda wants shoppers to "highlight products or services that don't deliver real value" and is creating what it described as "the UK's most comprehensive open-access point" on its web site for them to do so.
Asda chief executive Andy Bond said: "We're engaging with our customers in a transparent way to ensure the products we sell and the prices we charge meet their needs in these difficult times."
Additionally, Asda is launching a Saving You Money TV channel on YouTube, enabling consumers to swap cash-saving tips.