A survey showed that almost 1.5 million people could skip a meal in the coming weeks because they don't earn enough to put food on the table for the whole family.
A lack of free school meals during the holidays and rising costs are cited as the main reasons for the issue.
The trust, which runs hundreds of foodbanks across the country, is launching a national programme of holiday clubs, offering activities and food to parents and children.
Many of the clubs will be held in churches.
Adrian Curtis, foodbank network director of the Trussell Trust, said: "Families who rely on free school meals during term time can find themselves facing hunger in the school holidays, when there is an extra financial pressure to provide main meals.
"No one knows the full scale of hunger in the school holidays yet, but these figures make one thing clear: many families are closer to crisis than we think.
"It should be a wake-up call to us all that so many children will have a parent expecting to skip a meal or more this summer so they can feed the family.
"Foodbanks already provide additional help to families who struggle to put food on the table outside of term time, and our summer pilot of holiday clubs is a crucial step in broadening the support offered by foodbanks in the holidays."
Last year, the Trussell Trust saw 5,000 more emergency food supplies given to children by foodbanks in July and August compared to previous two months.
Anne Danks from the Trussell Trust speaking to Premier's Aaron James: