Campaigners say Llanwrda post office serves nine rural communities
Campaigners fighting the closure of a Carmarthenshire post office near Prince Charles's rural Wales retreat are writing to him for support.
Members of Llanwrda action group want the prince to revoke the word "Royal" from the Royal Mail's title.
They claim the post office serves 1,500 people in nine communities, not the 274 which the Royal Mail says it does.
The Royal Mail said the action group's views would be taken into account before a final decision was made.
The village, at the junction of the A40 and the A485, is some six miles by road from Llwynywermod, the 192-acre retreat Prince Charles bought in 2006 as a base for his visits to Wales with the Duchess of Cornwall.
The royal couple are spending their first week in the property following its extensive makeover.
Campaigners say Llanwrda's village shop will have to close if the closure of the part-time post office goes ahead.
Their letter to Prince Charles claims post office bosses have "misunderstood the role the post office and village shop plays in rural life".
Action group chairman David Darrell said: "Over the past 10 years or so, all the other villages around here lost their post offices, so there were fewer post offices in the area to start off with.
"The post office has got to close 2,500 post offices and do it in a way that no one group of people are more affected than other groups. But we had fewer post offices to start with."
Mr Darrell said alternative post offices would mean a trip of up to 17 miles for some people.
The action group said its letter to Prince Charles was in the post.
It reads: "We are calling upon the Welsh's 'people's prince' to demonstrate that the way the people are being treated and disregarded is not acceptable and not the standard acceptable to a holder of the title 'royal'".
In a statement, the Royal Mail said it had checked the figure in the 2001 census for the population within a mile of the village and it was 274.
A spokeswoman added: "Taking the decision to close any post office branch is always very difficult and we know it causes concern to many of our customers.
"We are currently out to public consultation on proposed post office closures in south and west Wales which will continue until July 14.
"We are attending public meetings and receiving representations from local community groups and we are aware of the individual and group representations that have been made regarding Llanwrda Post Office."