Campaigners have barricaded themselves into a boatyard to stop bailiffs clearing the site for developers.
British Waterways has secured a court order to remove the boaters, who are living illegally in Castle Mill Boatyard in Jericho, Oxford.
They are opposed to redevelopment plans including restaurants, boat hire facilities and luxury housing.
British Waterways said it had the power to remove the "illegal occupiers" and was looking for possession of the site.
The residents, who should have left by 9 May, have lifted eight narrow boats onto the wharf to make clearing the site difficult.
Adrian Arbib, spokesman for the boatyard's residents, said: "We have lifted our boats out for essential maintenance and also because it they will be more difficult to remove when out of the water.
"They [the yard's residents] are prepared to battle to the end to preserve their homes and prevent the extinction of an historic, low-impact way of life."
A spokeswoman for British Waterways said: "We are fully authorised to remove illegal occupiers now. We are looking for possession of the plot."