If the co-location goes ahead, the new office will house about 500 staff from five existing Newcastle tenancies and result in the Mayfield and King Street, Newcastle, Centrelink offices closing.

The EOI document seeks expressions of interest in providing an 8100-square metre office somewhere in an area covering Waratah, Georgetown, Hamilton North, Hamilton East, Broadmeadow, Newcastle West, Wickham, Maryville and Tighes Hill.

It says the new "high-quality" building must have "good" access to public transport and parking. The offices must have 12 parking spaces, including two for customers.

The lease will be for 10 years, with two more five-year options, in an existing or proposed building.

The tender opens the door for a developer to build another large office block in Newcastle as no existing building in the city fits the department's criteria.

A spokesman for Core Project Group said it would submit an EOI to Human Services for its DA-approved 727HQ building at 727 Hunter Street, which has 11,000 square metres of floor area for lease.

The only other DA-approved building of sufficient size in the city is GWH's Darby Plaza building in Hunter Street, at 8000 square metres, but it is outside Human Services' prescribed geographic boundary.

Doma's 16,600-square metre, 12-storey Store office building under construction beside the Newcastle Interchange has an anchor tenant in the NSW government.

Knight Frank agent Ross Cooper said the company had received a "very late" flurry of interest last week from developers interested in turning the 5100-square metre Dairy Farmers Corner site into a possible home for Human Services.

Newcastle MP Sharon Claydon, who revealed the Centrelink merger plan 10 days ago, renewed her attack on the Morrison government on Tuesday after seeing the EOI document.

"It's absolutely ridiculous that only two car parking spaces will be provided to customers, despite the fact that this new location is supposed to deal with the combined customers from two very busy Centrelink offices," she said.

The document mistakenly refers to Broadmeadows, a suburb of Melbourne, and Tighes Hills.

"It's clear from the complete absence of local insight that this tender was developed in a bureaucrat's office in Canberra without consulting the community that's actually going to be affected. This is unconscionable," Ms Claydon said.

"Not only are suburbs spelt incorrectly, but many are inappropriate.

"Not one of them could possibly provide an adequate substitute for the two existing Centrelink offices that the Morrison government plans to close."

Department of Human Services general manager Hank Jongen said earlier this month that "no departmental jobs will be lost due to this change".

Human Services also provides Medicare and Child Support services, including family assistance.

The department's office consolidation continues a shake-up in Newcastle's commercial real estate landscape.

City of Newcastle moved 450 administration staff from the Civic precinct into half of the Gateway 2 building in Stewart Avenue last month.

The state government will also co-locate hundreds of staff from various Hunter agencies when the Store building is finished.

Doma sold a seven-storey, 6500-square metre commercial building in Honeysuckle Drive to IOOF Investment Management for $52 million in June.