Marks & Spencer and Ocado are the only supermarkets to have sat out a healthy eating initiative supported by 92 per cent of the grocery market.
Peas Please, which was created by the Food Foundation, commits businesses to reporting and increasing their vegetable sales.
For example, Tesco has said that 66 per cent of its ready meals will contain at least one piece of fruit or veg by 2025, up from 50 per cent last year.
Companies that have put their names to the pledge have served an extra 636 million vegetable portions since 2018.
However, Food Foundation project manager Rebecca Tobi told the Grocery Gazette that Marks & Spencer and Ocado were “the two major retailers yet to join the scheme”.
She added: “We would very much like to see more engagement from the convenience store sector – especially given that they are often situated in more deprived or isolated areas.”
McColl’s and Londis have not signed up to the initiative, although Spar Northern Ireland has.
“Transparent and regular reporting against targets is vital if we are to turn the tide on our current dietary crisis,” Food Foundation executive director Anna Taylor said.
Low consumption of vegetables and pulses is associated with 18,000 premature deaths every year.
The news comes after supermarkets were criticised for seeking further delays to the banning of multi-buy promotions on junk food.
A survey last week showed nine in 10 grocery bosses wanted an extra six months before bringing in the rules, which have already been pushed back once.
“This is a time for speeding up and expanding action, not seeking further delays and undermining progress towards a healthier nation for all,” healthy eating campaigner Barbara Crowther said.
Marks & Spencer and Ocado, which launched the joint venture Ocado Retail last year, have been approached for comment.