“Because the poorest students will now be receiving maintenance loans, rather than grants, they will come out with more debt than their richer colleagues, which is absolutely appalling.”

In Westminster last week Alison Thewliss, an SNP MP, railed against the injustice of poorer students in England leaving university with higher debts than richer students.

But she forgot one thing: the same is also true in Scotland. North of the Tweed, the poorer your family is the more debt you graduate with. Scottish students from families earning £16,999 or less will graduate with £5,000 more debt than those from families earning over £34,000, as research from Lucy Hunter Blackburn shows. And students who are assessed as mature and independent of their families (who are disproportionately from poorer backgrounds) get lumbered with £8,000 more in debt than students from the wealthiest families.

Loading debt onto poor Scottish students has not happened in spite of the SNP – it has largely happened because of them. Over the past 15 years, the SNP has faced a choice: prevent students, who are disproportionately middle-class, from having to pay any tuition fees, or invest the money in more generous grants to help poorer students with their living costs.

Its decision (and one supported by Scottish Labour, the Liberal Democrats north of the border and even the Scottish Conservatives for a period) not to introduce fees is populism for the middle-class. Maintaining free university tuition while cutting student grants has amounted to a £20m transfer to middle-class students at the expense of less advantaged ones, Hunter Blackburn has calculated. In 2013/14 alone, spending on grants for low-income students was cut by 40 per cent.

And in reality the effect has been even worse. Because Scottish universities cannot charge tuition fees, the money they have to spend on bursary and outreach programmes is inadequate. English institutions spend over three times as much on financial help for poor students, according to a 2013 study.

This goes a long way towards explaining why Scotland has such a terrible record getting its poorest students into university. The richest Scottish students are 3.53 times more likely to enter university via UCAS than the poorest one, compared with 2.58 in Northern Ireland, 2.56 in Wales and 2.52 in England. For a poor young person wishing to go to university, Scotland is easily the worst country in the UK to grow up.

Perhaps Thewliss does not agree with the SNP’s higher education policy – though she has never said as much. Perhaps she did not know the facts about what had happened in Scotland. Or, most likely, she simply did not believe that anyone would pick up her inconsistency: the SNP is not used to being challenged.

It is a reminder of a wider truth. While the SNP delights in haranguing Westminster for what is happening in England, the party would be wiser to focus on Scotland’s many problems.