Disappointed customers are calling for a rethink after a specialist food shop was forced to close at Blickling Hall because the National Trust would not renew its lease.

More than 70 people have signed up to a Save our Samphire group page on social networking site Facebook set up by one angry customer, and another has protested about the closure on her online blog, attracting more than 50 comments.

Campaigners believe the Trust's actions run counter to its ethos of championing quality, local food and fear it could set up a 'corporate' business in place of the acclaimed Samphire.

But the Trust insists it is just as passionate about celebrating local food, which it uses in its restaurant and sells, and annually ploughs more than �1m into the local economy.

Samphire, based in a barn beside the car park at the stately home, near Aylsham, shut its doors on Monday after five-and-a-half years.

Owners Karen and Jeff Nethercott also closed their satellite shop in Wymondham which was not sustainable alone, with a total loss of five jobs. The closures have affected up to 150 Norfolk suppliers.

Tina Gibbons, who set up the Facebook group, said she had been devastated to learn about its closure and amazed when scores signed up to the SOS group within 24 hours.

Ms Gibbons, 37, from Norwich, grew up in Ingworth, near Blickling, and often treated herself to Samphire's cakes and pork pies – dubbed The Perfect Pork Pie by food writer Giles Coren.

'The National Trust say they want to enhance the customer experience –that's exactly what Samphire was doing,' she said. 'They should be supporting them, not closing them down.' She also plans to write to other celebrity chefs for support.

Food blog writer Victoria Currell has written an open letter to Trust director general Dame Fiona Reynolds 'begging' her to reconsider. She writes: 'Without Samphire, Blickling becomes just another National Trust property, with the same corporate feel that the National Trust is beginning to have wherever you go.'

Helen Bailey, Blickling general manager, said they would not be replacing Samphire with a corporate copy of a farm shop, or try to take advantage of its success.

'We have felt for many years that we are doing our visitors a disservice in this particular area as people arrive and we plan to totally transform it,' she added.

'We also have to compete in an area of Norfolk that has much to tempt people and if we don't respond to their needs then the chances are they will go elsewhere.'

Mrs Nethercott, 48, said Monday had been a sad and emotional day as they moved out and they would be back 'like a shot' if the Trust had a change of heart.