Footballer Marcus Rashford and chef Jamie Oliver are among the signatories of a letter sent to the prime minister calling for an urgent review into free school meals.
Other signatories included Tom Kerridge, Hugh Fearnley Whittingstall and more than 40 NGOs, charities and education leaders.
The letter, co-ordinated by the Food Foundation, called on the government to:
• Review the current eligibility thresholds for free school meals across all four nations to eliminate disparities. • Urgently consider how funding for free school meals can deliver the biggest nutritional and educational impact, including whether the allowance for free school meals is adequate. • Explore how schools can be supported to deliver the best quality school meals, including mandatory monitoring and evaluation. • Consider how existing school food programmes can eliminate experiences of stigma for the poorest students.
The letter emphasised that the process should involve input from all the devolved nations and be done in consultation with children and young people, as well as teachers, charities, NGOs, frontline catering staff and school meals service providers.
The call follows a photo of a Chartwells free school meals bag posted on social media by one mother, which went viral and was widely criticised, with footballer and child hunger campaigner Marcus Rashford describing it as "unacceptable". Boris Johnson branded it "disgraceful".
Chartwells, a member of the Marcus Rashford Child Poverty Taskforce, has said it will be adding free breakfast to its food parcels as well as refunding the costs of 'hampers' that did not meet "our usual high standards", contacting every school "to understand where any shortages may have occurred" and apologising to those affected.
Robin Mills, managing director of Chartwells' parent company Compass Group UK & Ireland, has also stepped in and publicly apologised, and said the group will offer schools lunch parcels through the February half-term at no cost.
In a statement, Mills said extra protocols have been put in place, including quality assurance checks at both supplier level and within schools, a free helpline for schools and parents that will go live on Monday, and a move to one-week parcels to include more fresh produce.
Mills added that the group is committed "that we make no profit on the provision of food parcels".