There are few more emotive topics than the prospect of building on green belt land.

But Birmingham councillors need to balance the desire to protect the green belt with the need to provide homes for the city’s citizens.

They also cannot be blind to the economic benefits of supporting the construction sector at a time when unemployment is high.

So we would not rush to judgment over the local authority’s refusal to rule out building on green belt land. If the council cannot reasonably promise to preserve every square foot of green belt land for eternity then it should not pretend otherwise.

But councillors also need to be aware of the strength of feeling that would be aroused if the green belt was threatened. If building was to take place there, it could only be as a last resort.

And it is far from clear that such desperate measures are needed.

Can councillors claim that they are certain there are no empty properties in Birmingham that could be made available for housing? We are frequently told that many such homes do exist, even if they would require extensive refurbishment.

Is there no brownfield land that could be reclaimed for residential use? It’s true that industry also requires land, and that some brownfield sites would require expensive detoxification before they could be used for homes, but it’s far from clear that councillors have looked into this issue in any depth.

What about the land currently held by bodies such as the Homes and Communities Agency? As we also report, Birmingham and neighbouring authorities plan to use some of this land for housing as part of the “city deal” agreed with central government. Councillors should be ensuring every square inch of this state-owned property empire is put to good use.

There is, of course, an important distinction between the green belt itself – land which is safeguarded from encroachment - and greenfield land, which simply refers to land which has not been built on previously (or, in some cases, land where previous developments have blended into the landscape over time).

The green belt lies around the outskirts of West Midlands conurbation. In Birmingham’s case, that generally means towards the east of the city. This is not necessarily where new housing is needed.

Protecting any green space in Birmingham is highly desirable. But if that really does prove to be impossible then councillors could look towards using other greenfield land before considering building on the green belt.

The truth is that we hear, again and again, arguments that the green belt cannot be sacrosanct, and that it must be built on for economic reasons or to cope with population growth. Birmingham City Council may be right to take a practical rather than a dogmatic approach to the green belt, but it would require the most exceptional justification to start chipping away at it.