It's difficult to miss the irony. The parents of the child star who played Matilda in the West End musical about a prodigy's struggles in a difficult school environment are facing prison for not sending their prodigy to school.

Edward Hardy and his wife Eileen Tracy have always homeschooled their 12-year-old daughter, Lilian. After being cast in the title role, an application for her performing licence put her on the radar of Westminster City Council. Despite her parents sending in samples of her work and activities, this was not enough.

The Department for Education has issued guidelines for local authorities which say that local authorities 'have no statutory duties in relation to monitoring the quality of home education on a routine basis'. Under the Education Act 1996, where they have reason to believe that parents are not providing a suitable education, they can require the parents to 'satisfy them...that the child is receiving [a suitable] education'.

Westminster went much further than this, claiming it has its 'own policy' and demanding either an inspection with Lilian, or an endorsement by an evaluator. Because the family have refused to submit to Westminster's specific demands, they have been ordered to send Lilian to school by March 7. If they do not, they face a criminal conviction and a fine. If that fine remains unpaid, they face prison.

These demands are not only out of step with Government guidelines, but also with international law. The Universal Declaration of Human Rights – often described as the constitution of the entire human rights framework – says that parents have a 'prior right' to direct the upbringing of their children. The former UN Special Rapporteur on the Right to Education, Vernor Muñoz Villalobos, stated, 'distance learning methods and home schooling represent valid options ..., bearing in mind that parents have the right to choose the appropriate type of education for their children... The promotion and development of a system of public, government-funded education should not entail the suppression of forms of education that do not require attendance at a school.'

And yet this prior right is one coming under increasing threat from a growing state – not just in Westminster but also in Europe. I represent the German Wunderlich family at the European Court of Human Rights. They too chose to homeschool their children and were met by the full force of the German government. One quiet morning, more than 30 police officers and social workers stormed the house and seized their four children. They carried the crying children out of the house.

Over a three-week period, the authorities subjected them to a battery of tests and examinations in an attempt to find fault with the education provided by their parents. To their certain annoyance, the test revealed the children to be performing at the same level as the average state school student. Eventually – after three weeks – the authorities were obliged to return them to their parents.

The European Court of Human Rights has agreed to hear this important case. Its decision will have an impact, not just on the Wunderlichs and other German families, but also on cases like this one across Europe.

Back in the UK, the relentless pressure on home educators grows, with a bill in the House of Lords which would introduce 'a duty to monitor the educational, physical and emotional development of children receiving elective home education in their area'. The idea of Miss Trunchbull turning up at the doors of homeschoolers to assess their 'emotional development' should worry every parent. With vague powers like that, this bill would only worsen the current plight of parents facing down powerful officials.

As Lilian sang in the one of the show's hits, 'Just because you find that life's not fair, it doesn't mean that you just have to grin and bear it. If you always take it on the chin and wear it, nothing will change. Even if you're little, you can do a lot. If you sit around and let them get on top, you might as well be saying you think that it's OK, And that's not right.'

Matilda, we agree.

Robert Clarke is a barrister and Director of European Advocacy for ADF International.