You've got to give Ed Balls credit for making his position clear.

He doesn't like selective education - but he's not go-ing to scrap it in cities such as Birmingham.

This is what he told headteachers as he visited the city yesterday, where he received a warm reception.

Some may criticise Mr Balls for failing to take his arguments to what may appear to be their logical conclusion, and announcing an end to grammar schools.

However, he is right to argue that it is up to local education authorities - who are accountable to local voters - to make their own decisions.

His complaints about selective education are less easy to defend.

The Schools Secretary said that secondary moderns in selective areas started off with a number of disadvantages, including a sense among some pupils that they had already failed.

It's debatable whether Birmingham has enough grammar schools to imply that the remaining secondaries should be called secondary moderns rather than comprehensives.

Certainly, there will be many pupils in the city's state education system who have never taken a grammar school entry exam, for a variety of reasons.

But more importantly, the implication of his argument is that similar problems do not exist in areas without grammars. And this is plainly untrue. The comprehensive system has not changed the fact that some pupils enter school with high aspirations, while others expect little from education, and have little expected of them.

Every parent knows that there are schools where pupils are likely to do extremely well, and others where even the brightest youngster is unlikely to gain the kind of results needed for a place at a top university.

The difference, in an entirely "comprehensive" system, is that entry to the most successful schools is determined entirely by postcode - in other words, by whether parents can afford to live in the right neighbourhood.

In practice, which system offers the best hope for a bright child in a deprived area with little tradition of educational achievement?

This is the system a party which believes in social justice should support, and evidence suggests it is a selective system.