Parents are desperate to get their children into a good state school and - increasingly it appears - will go to any lengths.

Pushing against this are the councils, which are under pressure to stop middle-class parents from monopolising the best schools, which are often highly oversubscribed.

The Government tightened up the admissions code last year in an attempt to make school entry fairer but, inevitably, there are ways around this.

Tactics used by families have included suddenly discovering God, to get their child into a good Church of England or Roman Catholic School, and moving as close as possible to the school to be within the catchment area.

In some parts of London this can add a six-figure premium to house prices, excluding all but the very wealthy.

Some, refusing to be thwarted, make up in guile what they lack in funds. One common practice is to rent a flat within the catchment area during the application process.

Schools have become suspicious when noticing the same address coming up year after year. One alert head teacher caught parents out by going round in person to check that they lived there.

Other councils have spied on families using laws set up to track terrorists. One couple and their three children were unwittingly put under surveillance by Poole Borough Council for more than two weeks to find out if they really lived in the catchment area of a good school.

The latest case in Harrow is particularly significant because the council was the first to attempt to take legal action against a parent over school admissions.

By dropping the case, because of fears about legal costs and uncertainty that the Fraud Act was a suitable recourse, it leaves unanswered the question of what sanctions councils can take against parents who flout the rules and under what laws.

Removing a pupil from school if their parent is found to have lied punishes the child.

If it is serious about tackling the problem, the Government will need to work with councils to close this legal loophole.

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