England football star Marcus Rashford vowed to keep campaigning to extend free school meals over the holidays after MPs voted against the measure.
The Manchester United player told politicians to "stop stigmatising, judging and pointing fingers" as he warned a "significant number" of children will go to bed hungry and "feeling like they do not matter" because of comments on Wednesday.
He called on people to "unite" to protect the most vulnerable children, adding: "For as long as they don't have a voice, they will have mine."
Rashford released a statement after Labour's motion, which called for the scheme to be extended over school holidays until Easter 2021, was defeated by 261 votes to 322 – majority 61.
Five Conservative MPs rebelled to support the motion, including Education Select Committee chairman Robert Halfon, but it was not enough.
The division list showed the other four were Caroline Ansell (Eastbourne), Jason McCartney (Colne Valley), Anne Marie Morris (Newton Abbot) and Holly Mumby-Croft (Scunthorpe).
Downing Street ruled out performing a late U-turn ahead of the vote, with Prime Minister Boris Johnson telling MPs that support will continue for children on low incomes.
"We will continue to use the benefits system and all the systems of income to support children throughout the holidays as well," he added.
Several Conservative MPs argued against Labour's proposal, with Brendan Clarke-Smith (Bassetlaw) saying he did not believe in "nationalising children".
He told the Commons: "Where is the slick PR campaign encouraging absent parents to take some responsibility for their children?
"I do not believe in nationalising children.
"Instead, we need to get back to the idea of taking responsibility, and this means less celebrity virtue-signalling on Twitter by proxy and more action to tackle the real causes of child poverty."
Tory David Simmonds (Ruislip, Northwood and Pinner) also said: "What does it say about the Opposition's priorities that all of their interests are simply swept aside in favour of currying favour with wealth and power and celebrity status, spending taxpayers' money to curry favour with celebrity status, wealth and power.
"Now I have no doubt that Mr Rashford is an expert in his own experience, but we should not forget that the experiences he so movingly described took place under a Labour government then supposedly at the peak of its powers in tackling child poverty in this country."
Tory minister Paul Scully also told the BBC that "children have been going hungry under a Labour government for years" and insisted the Government had been tackling the issue.
But Conservative Mr Halfon urged the Government to continue providing meals over the holidays while the coronavirus crisis was ongoing and called on ministers to work with Rashford.
Reacting to the vote, Rashford said: "Put aside all the noise, the digs, the party politics and let's focus on the reality.
"A significant number of children are going to bed tonight not only hungry but feeling like they do not matter because of comments that have been made today.
"We must stop stigmatising, judging and pointing fingers. Our views are being clouded by political affiliation.
"This is not politics, this is humanity."
Rashford added that child food poverty "has the potential to become the greatest pandemic the country has ever faced".
He said: "We must start working together and unite to protect our most vulnerable children. No more sticking plasters. Let's face this head on."
Rashford continued: "I don't have the education of a politician, many on Twitter have made that clear today, but I have a social education having lived through this and having spent time with the families and children most affected.
"These children matter. These children are the future of this country. They are not just another statistic. And for as long as they don't have a voice, they will have mine. You have my word on that."
For Labour, shadow education secretary Kate Green said: "Boris Johnson and the Conservatives have badly let down more than one million children and their families.
"No child should go hungry over the holidays, but the Government is blocking the action needed to prevent this.
"We pay tribute to Marcus Rashford and others for shining a spotlight on this incredibly important issue.
"This campaign is not over and the Government must reconsider."
Kevin Courtney, joint general secretary of the National Education Union, branded the result of the vote as "callous", adding: "No MP who voted against this will be going hungry tonight, not one of them will be wondering where their next meal is coming from and not one of them will struggle through every single day with insufficient food.
"This isn't right. No child should return to school after the half term break too hungry to learn."