The clause proposes that the purpose of the UK's national parks and areas of outstanding natural beauty - to conserve beauty - can be overridden.
The government wants to do this to allow certain types of infrastructure to be built, the Campaign to Protect Rural England (CPRE) said of the protection, which has been in place for over 60 years.
It is most worried about telecoms such as broadband.
"We are very concerned that the clause could be used to deregulate planning controls over mobile phone masts and other forms of communications infrastructure," said a spokeswoman for the CPRE.
"Campaigners and politicians from all sides of the house do not believe the Government has provided good evidence to support the claim that existing protections for our most valued landscapes have prevented the rollout of broadband. The powers in the bill are far too wide ranging and set a dangerous precedent."
CPRE senior parliamentary officer Adam Royle said: "We are alarmed by the proposals in this Bill. Protections for national parks and areas of outstanding natural beauty have been in place since 1949 and maintained by successive Governments.
"We strongly support the extension of broadband to all areas, but this can be achieved without damaging the beauty of our most special landscapes. These new laws will establish a deeply damaging precedent for the nation’s most beautiful landscapes.