Ministers' attempts to save playing fields have been "disastrous", a group has claimed.
The government says it is preserving sporting facilities
But government departments and other campaigners say the National Playing Fields Association (NPFA) is being "unnecessarily alarmist", as it has become harder to sell off land.
Construction bids for sports fields in the past year amounted to 1,325 - more than double the 625 in 1999-2000, according to official figures cited by the NPFA.
For school sites, applications rose from 314 in 1999-2000 to 551 in 2001-2.
NPFA director Elsa Davies said: "The figures themselves are disastrous.
"They show that nothing the government does is working, that its promises have been trampled underfoot in the apparent rush to build on green space."
But the Department for Culture Media and Sport (DCMS) said strengthened regulations on school field planning applications - put in place in 1998 - had made it more difficult to do away with them.
They ensured any loss of land would be made up for with other facilities and that money raised would go back into sport.
Sport England, the agency which has to be consulted on playing field planning applications, has raised no objections in 80% of cases.
A DCMS spokesman said: "A higher number of applications does not mean does not mean there will be a greater detrimental effect on sport."
A Department for Education and Skills spokesman said: "Since a law was implemented in 1998 to stop the indiscriminate sale of school playing fields, the number of playing field sites sold has reduced dramatically.
"An application for planning does not automatically mean the loss of school playing fields. For example, we know from Sport England that there are some 500 planning applications to build full size all-weather pitches on school sites."
Sport England is putting together a "Domesday Book" on school sport, to find out the amount of facilities available and what others need to be provided.
Harder to sell
Ken Davies, director of the charity Learning Through Landscapes, added that the number of cases of "disposal" - the selling-off of school playing fields - had fallen since the guidelines had changed five years ago.
He said it had become harder to get rid of grounds, continuing: "We would be as concerned as anybody."
Rules on school field sell-offs
Adequate playing fields for school and other local schools must be provided
Community use of facilities must carry on - e.g. football team use
Funds raised by land lost must be reinvested in sport
But Ms Davies, of the NPFA, said Sport England's protection did not necessarily cover land used for non-sporting recreation - like walking dogs or cycling - which could be lost.
She said: "Our hope in gathering figures is that they would help shape policy to stem the loss of playing fields.
"We have not even reached the starting gate on policy yet."
Ms Davies said the government had been "beset by inertia", adding: "Anyone who believes this will make a difference probably believes in the Easter Bunny as well.
"Playing fields are under attack from all sides.
"What we have here is a government that has lost its way, a monitoring organisation that is falling down on the job and a host of individuals, schools and organisations who know only too well that land has significant financial value.
"The lesson is clear.
"If we want to protect playing fields, sports grounds and open spaces for our children and future generations, we will have to do it ourselves.
"We must question local authorities, put pressure on the government and let those official bodies, that are supposed to be working on our behalf, know that we will not accept half measures."