Borrowdale currently sits outside the eastern boundary of the Lake District

A public inquiry will open tomorrow to consider plans to extend two national parks.

Campaigners want to see the enlargement of both the Yorkshire Dales and Lake District national parks so they almost meet each other in the Lune Gorge.

The Campaign to Protect Rural England says the current boundaries reflect a historic omission.

An inspector will hear arguments for and against the expansion of the national parks to include areas such as the eastern Borrowdale in the Lake District area, and the remaining part of the Howgill Fells that currently fall outside the Yorkshire Dales national park.

The CPRE has joined with the Campaign for National Parks to support the proposals to extend the areas.

CPRE president Andrew Motion said: “The landscapes of England are timeless, but some landscapes are given special protection because they hold a unique place in the heart of the nation.

“The Lake District and Yorkshire Dales are two such places.

“We should take this opportunity to right a historic omission and extend these two national parks.

“I hope, as I know thousands of others also hope, that the inquiry starting now will recommend the four extensions of these two priceless, breathtaking places, and that the Government will endorse that recommendation if it comes.

“In doing so, they would leave a legacy for the nation that will be cherished for many generations to come.”

The remaining section of the Howgills would be incorporated into an expanded Yorkshire Dales national park

The current boundaries were drawn up more than 60 years ago and follow administrative limits from that era, for example, the old West Riding of Yorkshire.

The most recent public consultation into the extension plans generated more than 3,000 responses from local people and from across the country.

More than 90 per cent of those responses were supportive of the extensions.

A recent report found that national parks generated business turnover of £10.4bn and employment within parks grew by 2.7 per cent in 2012.

Campaign for National Parks president Ben Fogle said: “The landscapes being considered by this public inquiry are the finest undesignated tracts of countryside in England.

“National park status will not only help to protect the natural beauty and wildlife of these areas, but provide a much needed boost to the rural economy in these tough economic times.”

Jack Ellerby of Friends of the Lake District added: “Expanding the Lake District and Yorkshire Dales national parks would be a good news story for the Government.

“We hope that ministers will act swiftly to ensure that these beautiful landscapes are granted the national park status they so richly deserve.”

The inquiry inspector is due to submit his report to the Government in September.