Residents are accusing the Lands Department of ignoring its responsibilities by failing to step into a row over a blocked lane in a Sai Kung village.
They say the department approved construction of houses in Ho Chung village based on the fact it could be accessed by road, but had done nothing since a landowner dumped a pile of rubble in the middle of the lane last week.
The incident raised concerns that fire engines would not be able to reach the village.
Kwok said village representatives had signed an undertaking in 2000, pledging to provide a four-metre-wide access route through private land for vehicles and emergency needs so they could build the new homes.
She said homeowners had never objected to the road, and this should give lands officials grounds to enforce the pledge.
The latest obstruction is at least the third such incident in the village since 2009, and comes as the Ombudsman investigates emergency access in rural areas.
"I don't see any light at the end of the tunnel," said Wenlise Kwok Pik-yuk, a villager who is helping organise a petition to get the road reopened. The blockade has forced drivers of some 270 vehicles to find temporary parking spots, creating a hazard for other drivers.
One car almost went off the road as the driver tried to squeeze past all the vehicles forced out of their usual parking spaces, villagers said.
The Lands Department has not replied since September 16 to inquiries about its role in the row and why it cannot resolve the dispute. Village representative Cheung Kwun-yung could not be reached for comment.
An open letter sent out before the pile of rubble appeared indicated that the blockade was a protest by the landlord and village leaders against the Home Affairs Department's role in a clampdown on illegal excavation.
Kwok accused the Lands Department of turning a blind eye to the problem despite being fully aware of the situation and its history. "It definitely has a responsibility. It approved houses because of the existence of the access," she said.
Police have told villagers they will tolerate illegal parking outside the village for now.
Fire Services Department officials are also not taking action, saying the road is not a designated route. They say they first need a plan from the Lands Department showing the route.
But Kwok said it was not clear why the fire department would have supported applications to build houses in the past if it did not recognise the existence of an access route.
Villagers now plan to protest on October 12 in Sai Kung, Hang Hau and near government headquarters in Tamar, Admiralty.
Kwok said it was unfair for the department to shrug off any responsibility for keeping the access open. The landlord had given an undertaking to provide access, she said, so the department had a legal basis to take action.
"It should assist the villagers to deliver on their responsibility instead of leaving villagers to fight among themselves," she said.
Designing Hong Kong activist Paul Zimmerman said he suspected the Lands Department had failed to register the landlords' commitment to maintain access in their land leases.
People applying to build small houses are required to provide access for emergency vehicles if they plan to build at least 10 houses within a 30-metre radius.
If no access is possible, applicants must fit the homes with fire-prevention equipment and take other safety measures.
The Ombudsman launched an investigation in May into the government's handling of fire safety matters in villages.
The issue was put into stark focus in 2012, when two brothers, aged seven and eight, died in a blaze in a Pat Heung village house in Yuen Long. Fire engines could not reach the home because development had narrowed the access.