Basil Fawlty famously marvelled at his wife Sybil's talent for the "bleeding obvious".

It appears that Sybil has a rival in Ruth Davidson, leader of the Scottish Conservatives. Ms Davidson this week "revealed" the academic chasm between the attainment of young people from well-off families and those from the poorest backgrounds. Hold the front page.

It's encouraging that Ms Davidson and her party have belatedly come to realise that we have an equality issue and the gap between rich and poor isn't narrowing. They claim that underachievement of children in our poorest areas is all down to inept local authorities, fit only to empty our bins. All will be well if schools become more diverse, parents have a bigger say and more power is delegated to headteachers.

Ms Davidson and her colleagues are either naïve or disingenuous. The attainment gap between the haves and have-nots will never be closed through tinkering with schools and their governance. To claim otherwise reveals a fundamental misunderstanding of the issues and their complexity.

I spent a significant part of my career as a headteacher trying to raise attainment in the type of area that Ms Davidson has in her sights.

The staff were highly talented and committed. The quality of teaching was consistently high but it was a constant challenge to move attainment upwards. If we had been free of the council and I had been given more powers, would it have made much difference to what we did and what our youngsters achieved?

Possibly, but our school did not exist in a vacuum. It was part of a wider community and was profoundly affected by the issues that existed within that community. To raise attainment in a sustained way requires a holistic approach that addresses both the educational factors and the social and economic disadvantages that impact on youngsters' achievement.

Yet it is not rocket science to identify why children in leafy suburbs do better. They are better fed and housed, they have comfortable areas in which to study, they have access to role models and, if all else fails, they can call on private tutors. Above all they have hope.

It is apparent that Ms Davidson and her party colleagues are not students of irony. UK government policies are pushing more families into the mire. Far too many youngsters live in relative or absolute poverty. An increasing number rely on food banks for their next meal. Many act as unseen and unpaid carers. It is difficult to prioritise your homework when you are tired, hungry or cold.

Ms Davidson is correct insofar as raising attainment is all about higher aspirations, great teaching and role - modelling. However, that is only one side of the coin. The electoral record of the Scottish Conservatives over the past 20 years suggests that they know all about underachievement. To be taken seriously they need to offer policies that, yes, address poverty of ambition, but also tackle the social, economic and cultural poverty that is the real cause of the attainment gap.