So the Blair boys receive a little after-school coaching from private tutors. Well, Tony and Cherie are not the first middle-class parents to use their financial clout to try to give their children the educational edge. Home tuition is a growth area and the demand is coming from parents of ever-younger children.

Most of the arguments against extra coaching centre on the fact that it gives children from wealthy families an unfair advantage in exams. But determined, anxious parents can use their bank balance in a multitude of ways to get the best for their offspring.

Most obvious is to opt out of the state-funded system and go private. Several thousand pounds a year for 14 years can secure your child a place in a top performing school. More politically correct, but hardly any less expensive, is to move house into the catchment area of your chosen school. And those who like a challenge can exercise their right to choose a good school far from home.

Then there is the home environment. Computers with internet access, books, museum trips and foreign holidays all help children succeed at school - at a price. Seen in this light, private tuition is just one of many options open to parents who want the best education for their children, and can pay for it.

Many liberal-leaning newspapers, such as the Guardian, used this reason to absolve the Blairs for choosing extra tuition. But this misses an important point about home tuition. Extra tutoring does not mean parents are simply paying for “more of the same”. Most private tutoring relies on a fundamentally different approach to teaching. For one thing, no time is wasted on registers, notices, returning books, dealing with disruption, shuffling about from one activity to the next and generally staring out of the window.

When I last taught in a comprehensive, the lessons were 50 minutes long. With one particularly disruptive class we probably spent 40 minutes working out who was absent or just bunking the lesson, who needed work sent down to the “sin bin”, who needed to be removed for special needs teaching, and persuading Simon to stop banging his head on the table and Jack to get up off the floor. And that was on a good day. Even in the least disruptive classes, teaching that relies on group work, changing activities two or more times before reconvening for a whole-class plenary, watching videos or unspecific computer use wastes time.

Teachers today are expected to be skilled at charades as they wave their arms furiously at anyone who hints at something approaching the learning outcome of the lesson. In a frantic blind man’s buff they try to tease and coax answers out of children, leading them through a series of activities, and praying they will somehow reach enlightenment.

Old-fashioned whole-class chalk and talk removes this element of chance, of time wasting. But too much talk from the teacher is frowned upon, as I found out to my cost during observed lessons. The children I now privately tutor are no more intelligent than the comprehensive kids I recently said goodbye to. Yet my tutees perform better - as a tutor I can impart my knowledge freely to them, avoiding the guessing game lessons.

When the Blairs pay teachers from Westminster school a reported pound;50 an hour, it is my guess that this is what they are paying for - a teacher who is an expert and has the confidence to impart that knowledge.

What the Blairs have done stinks of hypocrisy, not for trying to gain an advantage for their children but for the fact that it shows the Prime Minister’s recognition of the limits of the teaching methods used in “bog-standard” comprehensives. Yet the Prime Minister does nothing to challenge the orthodoxy surrounding current teaching methods. It seems what’s good enough for our children just ain’t up to scratch for the Blairs.

Joanna Williams is a home tuition teacher in Kent.