Two leading campaign groups, Child Poverty Action Group Scotland and Children in Scotland yesterday urged ministers to follow the UK Government's lead and give every five-, six- and seven-year-old a free school lunch.
John Dickie, from CPAG, said: "With Scotland's families being battered by UK government tax and benefit policies, stagnating wages and soaring food prices, free healthy school lunches have never been so important.
"It is great news for children in England that this policy is now being adopted south of the Border but its vital the policy is now fully implemented in Scotland."
Jackie Brock, the chief executive of Children in Scotland, said: "We know education is a key factor in improving social mobility, but children will not be able to learn if they are hungry or suffering malnutrition.
"We are pleased to hear there will be money allocated in Scotland's budget and hope our politicians use it for the same purpose, to extend this policy to the children and families in Scotland."
Details of decision to give English pupils free meals emerged at the Liberal Democrat conference in Glasgow.
The UK Government will spend £600 million on the policy. The Scottish Government will receive approximately £60m as its share of the cash but can spend the money as it wishes.
The SNP pledged to provide free school lunches for all P1 to P3 pupils in their 2007 election manifesto. The promise has never been fulfilled though provision has been extended to children from low income families.
CPAG Scotland highlighted research suggesting take-up of free meals by those already entitled to them would rise by up to a quarter if all children in the school could benefit. Overall take-up of school meals would rise from just over 50% to three quarters, studies show.
In his budget last week, Finance Secretary John Swinney vowed to protect what he calls the "social wage" of free prescriptions for all, free bus passes for all over-60s and free university tuition.
Families on a range of benefits can claim free school meals. At present 22% of Scots pupils qualify.
A Scottish Government spokeswoman said: "Nearly a quarter of primary school pupils are currently registered for free school meals in Scotland and school meal uptake continues to rise. We are committed to expanding this provision further and, once we see the financial implications of this announcement for Scotland, we will examine how best to deliver that expansion."
Scottish Labour's education spokeswoman Kezia Dugdale said: "While this may be desirable I question whether it's the best use of money given the current economic pressures Scots are facing."