Birmingham City Council was at the centre of a bitter censorship row last night after officials decided to ban staff from accessing a website set up to exchange information about a controversial programme of pay cuts.

An unknown employee in the planning department is the brains behind www.birminghamsinglestatus.co.uk – which invites more than 40,000 workers to write about the impact of the council's pay and grading review.

Under the review, almost 5,000 staff will lose pay, some by as much as £15,000 a year, although 18,000 will be winners and pocket a salary increase.

The website asks staff to share details of the personal scores they have been given from job evaluation exercises in an attempt to assess the numbers of gainers and losers under the pay shake-up.

As the site began to attract hits on Wednesday, with users complaining about unfair aspects of single status, council IT bosses decided to pull the plug.

It was unclear last night who gave the order to ban the site, but the decision was backed by human resources cabinet member Alan Rudge, who warned the person behind the website might face disciplinary action if he or she could be identified and it could be shown that the facility was set-up in work time.

Coun Rudge (Con Sutton Vesey) said: "I certainly do not believe people should be setting up websites on our system. They wouldn't do it in the private sector, that's for sure."

The council said in a statement that the blocking order had been issued because views posted on the site conflicted with the local authority's policies.

The statement added: "Council internet policy states that employee access to websites which misrepresent council views or policies' should be prohibited. The website was clearly found to be in breach of this policy and access from the council's network has therefore been blocked.

"Pay and grading is a high profile topic for council employees at the moment, there are a number of mechanisms and forums through which employees can voice their views on this matter. The council is looking at additional mechanisms that will allow employees to voice their views."

Although the site has been blocked on the council network, it remains freely available outside of the Council House to anyone with access to a computer. Council staff can also continue to access websites such as ebay and facebook, as long as they do so during official breaks.

A message posted on the single status website reads: "Some bad news. Unfortunately it looks as if Birmingham City Council has taken the decision to block access to this site from within the council network.

"Access to the internet for personal use in your lunchtime etc is of course a privilege not a right but it has been decided the content of this site is inappropriate. I can only apologise to the many people who have told me how helpful and useful they have found this site. I hope you can find some other way of accessing it.

"One thing worth remembering is that it is not only the employees of BCC who can look at this site but the whole of the world wide web."

The censorship row alarmed Liberal Democrat members of the council's ruling coalition.

Moseley & Kings Heath councillor Martin Mullaney said: "This is crazy. A very silly thing to do. It will just wind up the workforce even more.

"Anyone can go home and look at this website on their own computer, so blocking it on the council network achieves nothing. Tensions are already high and this will make things even worse."

John Hemming, Liberal Democrat MP for Yardley and a councillor for South Yardley, said he could not think of a legitimate reason for blocking the site. He believed the decision had been taken by officers without political consent.

Councillor Jerry Evans (Lib Dem Springfield) said: "This does sound mad".

Ian Ward, deputy leader of the opposition Labour group, said the banning order was an "extreme reaction".

Coun Ward (Lab Shard End) added: "This is a very draconian step which infringes freedom of speech.

"If Coun Rudge is correct when he says that the pay and grading review is fair, then he should not mind a website dedicated to sharing experiences of council workers."