THE benefits of providing a free, nutritious meal for all school pupils are widely accepted.

Take-up increases, perhaps unsurprisingly, but not just among children whose parents previously had to pay. Studies have shown that significantly more pupils who were already entitled to free meals actually take them if more of their classmates are doing the same.

Pilot schemes a few years ago found overall take-up rose from just over 50% to 75% - which meant three quarters of children were developing a healthy eating habit. Free meals also reaped dividends as more pupils found it easier to concentrate on their work and behave appropriately in class. Add in the savings for families (£330 per child per year, as MSPs will be reminded today) and the policy begins to look like a sure-fire winner.

If, as expected, First Minister Alex Salmond uses a set-piece Holyrood debate today to announce plans to provide free meals for all pupils in the first years of primary school, he will win support not just from parents but from a powerful coalition of anti-poverty campaigners, children's charities, trades unions (including the Educational Institute of Scotland) and the Church of Scotland.

They have been stepping up pressure on the Scottish Government since September when, in a speech in Glasgow, Deputy Prime Minister Nick Clegg announced a £600 million programme to provide free meals for all P1 to P3 pupils in England. Suddenly, faced with action south of the Border and extra cash to follow suit in Scotland, it has become very difficult for the First Minister to resist calls to implement his own policy, one first promised in the 2007 SNP election manifesto but never delivered.

Introducing it now would also go some way to answering those critics who accuse Mr Salmond of holding back appealing policies, such as his pledge to increase free childcare, as referendum sweeteners, although a political dividend would be timely for the SNP. It might give parents reason to smile on the Scottish Government at the start of the next school year, shortly before referendum polling day.Party supporters would surely feel 2014, their big year, had got off to a flying start.

For all these reasons, both principled and political, hopes are rising for a major expansion in free school meals for Scotland's youngest pupils. Questions would remain, however, about whether providing free meals for all was the best use of public money at a time of shrinking budgets. At present, nearly one-quarter of pupils, from families on a wide range of benefits, can claim a free meal, and they do so increasingly as electronic canteen cash systems remove the old stigma of handing over a special ticket. Extending entitlement would, by definition, benefit the better off, though many families would no doubt welcome the extra help. An announcement on free meals would be cheered by many but would surely also provoke fresh debate about the Scottish Government's spending priorities and how sustainable some of its most popular policies might be, given the deep spending cuts to be imposed over the next three years.