MSPs should consider using the Scottish Parliament's "tartan tax" to fund better nursery education, according to an influential former minister.
Wendy Alexander, who was Lifelong Learning Minister, believes such an investment provides the greatest returns.
Charging an extra 3p in the pound to fund better early years provision was not currently a spending priority in Scotland, Ms Alexander said, although many other countries had invested more heavily in this sector.
"It would cost a lot of money but we need to have the debate," she said. Ms Alexander, a visiting professor at Strathclyde University, delivered an education faculty lecture this week on "Scottish education: staying ahead".
The tartan tax would raise about pound;750 million, she estimated, and this would provide 20 hours a week of free nursery care instead of the current 12 hours a week. Raising income tax by a further 2p in the pound would pay for holiday and after-school care for all children aged five to 14.
Ms Alexander said: "It doesn't come cheap, but these are the years where the returns from investment in later life are indeed the greatest. We need to think more systematically as the Nordic countries do about the notion of upbringing being a different experience."
Quality pre-school education reduced the incidence of special education needs from one in three to one in five, she said.
She believed there was strong evidence that the best pre-school experiences were delivered by family centres combined with nursery schools. To improve the current pre-school experience for children would mean employing more qualified staff and creating a new profession - the early childhood educator.
Ms Alexander called for action to tackle the "funding clutter" in early years education, citing the experience of the Jeely Piece Club in Glasgow's Castlemilk area. In one year, it had five funding sources, was monitored by four government agencies, had to provide 31 reports, had 11 visits, inspections and meetings, and had to prepare three separate financial accounts.
While primary schools were overwhelmingly doing a good job at teaching children cognitive (IQ) and non-cognitive (I can) skills, it was still the case that 26 per cent of pupils - 15,000 a year - left without having reached level D in reading and writing.
Schools should consider keeping pupils in the primary sector until they had mastered basic literacy skills, she suggested.
Secondaries not only lacked the dedicated resources to concentrate on literacy teaching, they also "quite rightly resent doing someone else's job". Discipline problems and performance were linked to poor literacy standards in secondary.
Ms Alexander said a system that prevented progression to secondary until basic literacy had been achieved would provide an incentive to pupils, parents and schools to prioritise literacy. Pupils would want to master literacy because they would want to stay with their peer group; parents would support the schools; and schools would be empowered to prioritise literacy.
The English white paper on education, published on Tuesday, proposed investing pound;10 million on one-to-one tuition in the early stages of secondary. A better place to do that would be at the P6-P7 stage, Ms Alexander suggested.
Turning to the poor educational performance in Scotland's most challenging and deprived areas - notably Glasgow - Ms Alexander cited the success of five London boroughs in not only meeting but overtaking attainment targets that they had been set in 1997.
Among the lessons from the experience of Islington, Hackney, Haringey, Southwark and Lambeth had been the importance of establishing strong leadership, using data well to identify problem schools and education authorities, and combining tailored support along with transparent accountability.
The London boroughs also benefited from the concept of "contestability" - three successful interventions in failing local education authorities and the creation of 60 city academies in London by 2010.
Ms Alexander stopped short of endorsing the Blairite vision of city academies which were free of local authority control, asking: "What drives up standards more? Is it structures or what happens in the classroom?
"I am convinced it is what goes on in the school rather than the label you give to the school."