The retailer said its customer research had shown shoppers considered price a key barrier to eating healthily. Morrisons often ran 50 or more fruit & veg promotions but wanted to go one step further by committing to a minimum number of deals, said director of policy David Scott.
"It's about telling our customers, 'every week, when you come to Morrisons, we can guarantee there will be at least 50 promotions across the aisle'," he said.
The promotions will range from price reductions on individual produce items, to multisave offers and 'more for your money' deals, where shoppers can buy greater volumes of produce for the same price.
Products covered by the guarantee include loose and packaged produce as well as prepared lines.
The Grocer revealed last week that high prices were forcing vulnerable groups and young people to cut back on their fruit & veg purchases.
Meanwhile, the final wave of the government's Change4Life convenience initiative was rolled out to London this week. The scheme, which is run in conjunction with the ACS, helps stores in deprived areas sell a wider range of fresh fruit & veg and prominently display it with Change4Life branding.
Costcutter, Londis and Nisa were among the 11 London c-stores that signed up to the scheme, in which 250 shops in England are now involved.
Public health minister Anne Milton described the promotion as a '"fantastic way of making it easier for people to pop around the corner to get fruit and veg".
Central government funding for Change4Life finishes at the end of this month but the ACS has pledged to help another 1,000 shops take part by next year.