Some of the country's most important wildlife sites are under threat from commercial peat extraction, experts say.
Peat bogs are one of the most threatened habitats in Europe
The Royal Society for the Protection of Birds (RSPB) says Solway Moss and Bolton Fell Moss in Cumbria should be declared conservation areas.
The government was urged to designate the sites Special Areas of Conservation (SACs) in 2002.
But the RSPB says it is still waiting for action.
The society wants the government to explain the delay, and more than 250 RSPB members have written to MPs calling for the two sites to receive SAC designation.
The RSPB says that for every day the government delays announcing the formal designation, commercial peat extraction is destroying more of the two important wildlife sites.
Dr Oliver Watts, environmental policy officer for the RSPB, said: "If someone proposed bulldozing Hadrian's Wall or Carlisle Cathedral to use the stones for a rock garden, there would be an international outcry at the loss of our heritage.
"But that's exactly what's happening to some of Cumbria's precious peat bogs."
He said peat bogs were home to a wealth of rare plants, birds and insects.
They were one of the most threatened habitats in Europe.
The RSPB says that while the removal of the peat from both sites is lawful, many extraction permits were intended to cover small scale, hand-cutting activity, and granted long before the conservation value of peat bogs was recognised.
In June 2002, English Nature, the government's wildlife advisory body, recommended both as sites of European conservation importance.
However, two years on, the UK has yet to put forward the two sites to the EU.