In her speech at the state opening of Parliament, the Queen said: "A bill will be introduced to give people greater access to the countryside and to improve protection for wildlife."

The new legislative programme will be welcomed by organisations such as the Ramblers Association, which campaigns against blocked footpaths and disappearing byways.

Landowners have said they put certain land off limits because they need to protect livestock from stray dogs, and their crops from ramblers' boots.

But the bill still allows them to close their land without seeking approval for up to 28 days a year, to take conservation, defence, land management and health and safety into account.

Many footpaths have been blocked by landowners

Although walkers might argue that landowners might exploit this to keep ramblers at a distance, the bill's architects had to ensure they allowed for government's wildlife protection pledge.

The bill would also introduce more Sites of Special Scientific Interest, with increased protection for them.

These areas, which are also often popular with walkers, were established by the Conservative Government under the 1981 Wildlife Act.

But in practice many have since been destroyed by farmers.

The new bill would introduce custodial sentences for wildlife species offences, such as releasing non-native species into the environment, or recklessly disturbing a place of shelter or a nest site.

It would also allow search warrants to be used in all species offences, and would enable police and wildlife inspectors to ask for tissue samples for DNA analysis.

Friends of the Earth director Charles Secrett welcomed the measures.

"Britain's most precious wildlife sites desperately need the protection the government is now offering - although wildlife outside these sites also needs help.