A 100-year-old landmark Birmingham city centre building is set for demolition amid claims workers are to begin pulling it down within days.

It is understood that controversial demolition work on Island House, on Moor Street, which has been wrapped in scaffolding and plastic sheeting for a week, is due to begin imminently.

The Birmingham Post reported recently that campaigners and council conservationists had called for the three-storey former office and college art centre to be preserved.

However, English Heritage has ruled that the building was not worthy of protection and owner Quintain Estates was able to demolish at will.

The city council’s planning committee, which had unanimously condemned the demolition, was told in a private session that an existing legal agreement, under which Island House should be restored, was not enforceable.

Lawyers advised the committee that the deal would only become active once building work on the remainder of Quintain’s City Park Gate scheme began.

Quintain says it has put the development on hold due to uncertainty over the proposed location for a high-speed rail station.

The committee was also told that approaches to English Heritage had fallen on deaf ears, as had special requests to Quintain to work with the city to find a solution which could save Island House.

Committee chairman Peter Douglas Osborn said: “We feared this would happen and are exceptionally disappointed. We have worked hard through all legal channels to stop the demolition.

“We are particularly disappointed that English Heritage was not prepared to grant it the protection of a statutory listing. Our legal and planning officers have advised us that we have no powers to prevent this happening.”

There was dismay at the demolition news from the campaigners on Twitter, although a spokeswoman for Quintain could not confirm whether the work had started.

The company has previously said that its City Park Gate development, which included the restoration of Island House, had been blighted by plans for a high speed rail station.

It is believed that the cost of keeping a crumbling historic building maintained, as well as empty building rates, has prompted the decision to demolish.