Scottish labour leader Iain Gray has declared that there must be a "break with the past" to deal with worsening attainment levels in Scotland relative to England, Wales and Northern Ireland - at a time when school spending is higher in Scotland than anywhere else in the UK.
Mr Gray made his unexpected statement in response to the latest report from the Centre for Public Policy for Regions (CPPR), and he has taken the unusual step of inviting its authors to meet him to discuss their findings.
The report from the think tank, which is a joint venture between Glasgow and Strathclyde universities, shows that spending per pupil in Scotland is well above those in the three other home countries - pound;6,326 per secondary pupil compared with pound;3,923 in Northern Ireland, pound;3,865 in Wales and pound;4,620 in England.
At the same time, using the measure of the number of pupils getting A-C results at GCSE and Standard grade, the performance in English, maths and science rose between 1998-99 and 2006-07 - everywhere except Scotland, where attainment declined. There are also considerable variations in spending and performance among the Scottish education authorities.
He said: "It would be an unforgiveable mistake to stick our heads in the sand and ignore this report." Since the statistics relate to a period when his party and the Liberal Democrats shared power at Holyrood, his comments will be interpreted as rebuking Labour's record.
But one senior Labour figure described the report as making a "direct and somewhat simplistic connection between bald costs and bald results, leading to an erroneous conclusion".
And economist Arthur Midwinter, who is a visiting professor at Edinburgh University, pointed out: "Higher expenditure reflects greater need and the geography of any given area, and we shouldn't assume that it should feed into higher attainment, which is a much more complex matter.
"I'm not convinced that the CPPR report has taken us any further forward in understanding the links between spending and performance."
John McLaren, the main author of the report, who was an adviser to the late First Minister Donald Dewar, agreed that much more work was required to understand what lay behind the figures.
His report points to some of the reasons for greater spending in Scotland - sparsity of population, concentrated pockets of severe deprivation, better pupil to teacher ratios and slightly higher teacher salaries. Other reports have commented on the fact that there are more pupils educated by local authorities in Scotland.
And, although the rest of Britain has caught up from a very low base with the previous lead north of the border - or overtaken it - Scotland still held on to the top spot in English and modern languages in 2006-07, and was second to Northern Ireland in science.