All primary pupils in England would get access to free school meals under a plan being laid before Parliament.
Labour MP Zarah Sultana is trying to change the law to widen the scheme to ensure no child goes hungry.
Currently, all kids in England get free school lunches until the end of Year 2 and then they only qualify if their household receives certain benefits.
Around 800,000 children living in poverty miss out on free school meals due to strict eligibility rules. The Mirror and the NEU are campaigning to widen the scheme to boost the life chances of needy kids.
Ms Sultana will bring forward a bill next week to extend free dinners to all primary school children.
"We're finding that actually it's a major issue when families simply can't afford everyday groceries. If they have to pay for school meals, provide packed lunches, it's another strain," the Coventry South MP told the Mirror.
"Making it accessible for everyone is an easier, simpler process - and every kid feels the same. You don't feel like you're disadvantaged because everyone's eating the same food and doing it together."
In a direct appeal to Rishi Sunak, she said: "We have an unprecedented cost of living crisis, this is not the time to prioritise tax breaks for the wealthiest people but to allow the poorest in our communities to not worry about food and bills and issues like that that are really putting people in really difficult positions."
Mum-of-two Laura O'Hara is worried about making ends meet when her 5-year-old son stops receiving free school meals at the end of Year 2.
She believes her family wouldn't qualify for free school meals at this point, despite receiving Universal Credit.
Her partner works at Jaguar Land Rover and she plans to go back to work when her 3-year-old daughter starts primary school next year.
The 38-year-old, who lives in Coventry, said: "The closer it gets, the more I'm going to be thinking about it.
"I tried to put my son on packed lunches but I couldn't afford to do it. It's hard to buy food for the week that will last, fruit as well and things."
Laura said that mounting bills are a "never-ending battle" and the family have had to cut their spending on food.
She said: "Electric and everything has gone up so we've had to put our food bill down, spend less on food. Really we should be spending more money on food as it's going up but we just can't afford to do that at the minute.
"We can't afford to add extra shopping when we have to pay extra money for other things like the gas and the electric... it's a never-ending battle."
She added: "I would love everybody to get a free school meal as then you'd know every child is definitely having a meal a day. Some people can't afford to buy them for their kids. That may be the only meal they are going to get.
"People can't afford to make hot meals, they can't afford to use the electric, they can't afford to use their gas. A lot of people are just resorting to giving them a sandwich."
Teachers have been calling for provision to be widened after seeing hungry children struggling to learn.
Kevin Courtney, NEU Joint General Secretary, said: "Millions of children are going hungry every day and it is our members who are at the front line of supporting them while the Government is gripped by inaction.
"Restrictive eligibility for Free School Meals, complicated registration procedures and the stigma in-built into a system that separates rich and poor mean that children are missing out on the support they need."
While the bill is unlikely to become law without Government support, it will force ministers to respond to mounting calls to widen the scheme.
