He says current policies covering housing supply were hindering, rather than helping, the provision of more affordable accommodation for local people, with the result that they were being relentlessly driven off the moor by the pressure for second homes.
Conservative Mr Liddell-Grainger, whose Bridgwater and West Somerset constituency covers much of the national park, was speaking after two Exmoor young farmers, William Lock and Ben Cowling, had addressed a rural housing conference in Westminster.
The event was hosted by the CPRE and Hastoe Housing – currently engaged on a housing project in Carhampton near Minehead.
And, said Mr Liddell-Grainger, it included some shocking testimonies of the way local housing need was being thwarted by the rigid application of all-purpose planning regulations.
“The point has been made that a house for an agricultural worker needs to have storage room for his outdoor clothes and equipment and room for his dogs and his truck as well as for a car,” he said.
“But by the time all that has been provided the property no longer rates as ‘affordable’ because under the regulations it has become too big.
“This situation is not helped by the attitude of planners which all too often amounts to merely telling people what they cannot do rather than helping them find ways around the obstacles.
“I am not surprised that developers often lose the will to live when dealing with the national park authority but what do surprise me are reports we are getting that other park authorities are a lot more enlightened.
“Local problems need local solutions. Exmoor is a special case and needs a special approach on the planning front.”
Mr Liddell-Grainger said there was an urgent need to simplify planning frameworks to allow suitable farmworkers’ homes to be built and to facilitate the building of low-cost succession homes, so that sons could not only take over but live on the farm when their fathers retired.
And he warned the entire Exmoor landscape could be at risk unless there was change.
“I still see too many Government appointees on the national park authority who have no experience of living there and whose only interest is conservation,” he said.
“It is now generally accepted that there is no conservation without farming. Equally there is no farming without farm workers. It is they rather than the second home owners who keep the moor looking as attractive as it is.
“We let them drift away at our peril.”