Plans to “market test” Birmingham prison have sparked predictable fury from the Prison Officers’ Association.

Under plans announced by Jack Straw, the Justice Secretary, private firms will be invited to bid for the task of managing the prison, commonly known as Winson Green.

The prison service will also be invited to submit a bid. However, given that the whole process has been prompted by warnings that the prison is poorly run, one has to assume Mr Straw hopes to see someone new take charge.

According to the Prison Officers’ Association, this amounts to privatisation, a word which is now applied to almost any decision public sector unions disagree with.

The prison will, of course, continue to be publicly-owned.

It is likely that managers will work for a private organisation which supplies services to the Ministry of Justice, rather than working directly for the state.

But the public will have as much control over how the prison is run as it ever did – and perhaps more.

Managers will win the contract by guaranteeing to provide specific services and meeting certain standards, and if they fail to do so Mr Straw will be able to dismiss them.

Even if their work is satisfactory they will need to justify their continued existence once the initial contract runs out and they are invited to tender for the right to stay in the job.

In practice, our elected politicians will probably have more influence over the way the prison is run than they do today.

A concern frequently raised by unions when the private sector is given a role in public services is that working conditions may deteriorate.

Unions play an essential role representing the interests of their members and are right to push for high-quality working conditions and wages.

But there is no reason to assume that the private sector will offer worse conditions – especially if it hopes to maintain, or improve, the quality of staffing.

Mr Straw’s other announcements contained few surprises but many people will welcome the decision to abandon plans for so-called Titan prisons housing 2,500 people.

He is still proposing to create large prisons, with places for 1,500 inmates. But most experts seemed to agree that smaller facilities offer more chance of rehabilitating prisoners and preventing re-offending.

Mr Straw denied his change of policy was prompted by concern over funding. That’s as may be but, whatever prompted it, it’s a change for the better.