Subpostmasters in the county have been forced to sign confidentiality agreements about their own branches and have been given no details of others in the area.

Full details on the future of the county's 27 post offices, five of which could close, will not be revealed until July 29 when a six week public consultation begins.

A spokesman for the Post Office said: "We can't announce details before the public consultation because we have found that if information gets into the public domain it can result in migration away form branches that may not end up on the closure list.

"Public consultation is an important part of the process but before the list is announced we have to be careful what gets into the media.When the consultation begins we will encourage subpostmasters to discuss the matter."

One campaigner has criticised the ban on releasing details, Jim Latham is a member of Communities Against Post Office Closures and has fought the closure of the post office in his local village of Rippengale, South Lincolnshire.

He said: "It is scandalous that the public area't being told, everybody deserves to know. The Post Office has devised this closure programme so it is dealing with one small group at a time. My advice for those concerned about closures is start campaigning from day one, six weeks in not a long time."

There are three options facing post offices, branch closure, a changed service such as mobile or part-time branches or to remain in their current capacity.

David Jones, Vale of Clwyd MP said: "There are a lot of people who are worried about this. I want as many post offices as possible to stay open. In a lot of rural areas the post office is the only shop and once that goes the whole community goes. The problem is that if you save one post office another will close."