Sunderland City Council has been told it must turn around the fortunes of the Software Centre by opposition councillors.
ChronicleLive has revealed the development is losing hundreds of thousands of pounds every year despite being heavily subsidised by the local authority.
The office block was built to provide accommodation for tech firms but, since it opened in 2013, has never turned a profit.
In 2017/18, the council poured £655,909 into the venture and recouped just £367,969.
The following financial year, the council slashed its subsidy to £575,009 but clawed back even less (£342,120) - the lowest ever return from the investment.
It's part of a pattern of losses previously uncovered by ChronicleLive over the development's six-year life.
Labour council leader Graeme Miller has promised Wearside taxpayers the losses will be worth it in the long-run.
But opposition figures have urged the council to take action immediately so taxpayers can see a return on their money sooner rather than later.
Liberal Democrat councillor Niall Hodson said: "I am worried there has been a bit of a 'build it and they will come mentality'.
"The concern I have, and I understand some tenants have too, is that the council hasn't proactively encouraged or supported businesses there.
"Where are the adverts? Where is the media presence? What has been done to leverage the partnerships and sponsorships aligned to the centre to promote and support new business?"
He pointed to a lack of high-speed internet connectivity as one issue the council could look to resolve to boost the sites attractiveness to business.
Conservative councillor Michael Dixon, who is a member of the economic prosperity scrutiny committee, said lack of parking and restrictions associated with the receipt of European Development Fund cash are drawbacks for the site.
He said his committee observed 'little progress' on rates of occupancy.
Coun Dixon added: "We are expecting another report either side of Christmas and I would expect the Council to have in place some concrete proposals to ensure taxpayers money is not being continually drained by this loss-making centre.”
Coun Miller previously said the Software Centre is 'an absolutely key investment for a city that is fast-growing its reputation as a tech hotspot' and a 'strategic' investment.
He said: "In the early years, while occupancy is building, incubator centres may have overheads which exceed their income from rents.
"However, this is recouped with dividends – not only through the creation of high-value jobs for residents in the city, as well as the economic benefits that brings through their spend in our city – but also, as the businesses set up in our hubs migrate to larger suites and indeed into their own spaces within the city."
