AFCD officials say the five areas, either surrounded by or jutting into the park, are suitable for incorporation in full or in part. This would presuppose that development in the parks was not favoured. Any construction, including small houses for indigenous inhabitants, would require approval from the Country and Marine Parks Board.

The proposals were submitted to the board before the summer break but not disclosed because of their sensitivity.

Once the board endorses the final proposals, the government will put them forward for a public consultation. If the board maintains its decisions, there will be a legislative amendment on the boundaries of the park.

Board member Dr Billy Hau Chi-hang refused to confirm details but admitted the board was divided. He also believed "political considerations are at play".

Such a proposal will almost certainly raise the ire of the Heung Yee Kuk, the rural affairs body that represents the rights of villagers. "The last thing officials want is a direct confrontation with the Heung Yee Kuk, which will make sure it won't lose even a single enclave," Hau said.

A further 160 hectares in six enclaves are deemed unsuitable to be folded in the park. But they might be covered by the less stringent statutory protection of land-use zoning.

The future of the Plover Cove plots is part of a larger assessment of 54 enclaves in eight country parks to see if they should fall into the parks or be protected by land-use zoning. Without either protection, such land is regulated mainly by land leases, many drafted in the early 20th century.

The assessment was launched in 2010 after illegal excavation at Sai Wan on Sai Kung's scenic Tai Long Wan coast. The beach is now covered by interim land-use zoning and approval is pending from the chief executive to incorporate it into Sai Kung East Country Park. Similar approval awaits enclaves at Kam Shan, in Kam Shan Country Park, and Yuen Tun in Tai Lam Country Park.

Sai Wan villagers are preparing a legal challenge. In addition, 17 of the 54 enclaves are also covered by interim zoning.

The boldest of the Plover Cove proposals - expected to draw "exceptionally strong protests" - is one to turn 40 per cent of the 90-hectare Lai Chi Wo enclave, including Mui Tze Lam and Kap Tong villages, into country park.

According to the initial assessment, four other enclaves - at Sai Lau Kong, Fan Kei Tok, Hung Shek Mun Tsuen and Lai Tau Shek - are suitable for full incorporation. Each is less than 10 hectares, sparsely inhabited and with little private land. The officials expect "moderate to strong opposition" to these proposals from villagers or the kuk.

Excluded are enclaves at So Lo Pun, Sam A Tsuen, Siu Tan, Kuk Po, Fung Hang and Yung Shue Au, where 35 to 57 per cent of the land is privately owned and strong opposition would be expected to incorporation. Under the proposals, they would be covered by land-use zoning plans, including village development.

Some green groups have expressed concerns that this would open the floodgates for uncontrolled small-house developments. For instance, an area big enough for 135 houses in So Lo Pun has already been approved for that purpose.

Designing Hong Kong chief executive Paul Zimmerman criticised conservation officials for choosing to give in to development pressures. "They have given up control and left it to the regime of land zoning and the small-house policy that no one has control over," he said.

The board affirmed revised criteria in 2011 that say private land should not be automatically excluded from the parks. It also says unless there is extensive and active human settlement, village houses and fallow farmland are seen as an integral part of the country park landscape.