Campaigners have launched a legal bid to save a row of port buildings that are set to be torn down.
Save Britain's Heritage says North East Lincolnshire Council's decision to approve the demolition of Grimsby's Cosalt Buildings is "legally flawed".
It claims the authority did not carry out the necessary consultations and has submitted an application for a judicial review of the decision.
A council spokesman said he believed "the necessary steps" had been taken.
Henrietta Billings, director of Save Britain's Heritage, said: "These buildings need urgent protection and rightful recognition and we are confident they can be retained and reused to regenerate this part of the docks, as part of a wider strategic approach to the site.
"We have been advised that we have good grounds for a legal review, and are keen to ensure that the demolition is robustly challenged."
She said the council had failed to consult Historic England, which has previously described the 19th and 20th Century buildings as "heritage assets"
Save Britain's Heritage says "stripping out" work has already begun in preparation for demolition and, as a result, it has applied for an emergency injunction to prevent further work.
The buildings are not listed and are not in a Conservation Area.
An application by Associated British Ports (ABP) to demolish the buildings in Fish Dock Road was approved by the council in May.
ABP has said it wants to ensure the port is able to provide space for an expected expansion of the offshore wind industry.
Speaking in May, a spokesperson said: "The demolition of these buildings will allow clients to expand their businesses and in doing so create jobs and much-needed prosperity for the community."