The Prime Minister has called plans by an Islamic group to march through the Wiltshire town of Wootton Bassett "disgusting and offensive".
Gordon Brown said the town had become a symbol for the whole country's commemoration of fallen soldiers.
The town has become famous for its repatriation ceremonies for troops killed in Afghanistan.
Islam4UK says it wants to parade empty coffins through the town to draw attention to Afghan war casualties.
The Prime Minister said: "I think the whole country is proud of the people of Wootton Bassett and the dignified way that they have commemorated the service of the soldiers in Afghanistan.
"It has become a symbol for the whole nation's commemoration and remembrance of the people who've served our country.
"I don't think there is anybody I know in this country who wishes to turn Wootton Bassett and what happens there into an undignified political event led by one or two people who've got malicious reasons for doing so.
"I think we should be very clear that it's not acceptable and it would be disgusting and offensive and I don't think there is any public support for any means by which Wootton Bassett should be abused in this way."
But Sir Hugh Orde, president of the Association of Chief Police Officers, said any march should be allowed to go ahead.
"People have a right to march. People might not like it, but that's it," said Sir Hugh, whose own experience of policing protests stems from his time as Chief Constable of Northern Ireland.
'Loyal and dedicated'
The Prime Minister said his "heart went out" to the families of those who had died in the conflict and to the people of Wootton Bassett who had been "loyal dedicated and patriotic".
"I do not want their good will abused by people coming in to disrupt what is an activity which is welcome throughout the country."
Islam4UK, said the town was chosen to create maximum publicity.
Spokesman Anjem Choudary said on Monday: "We are having a procession, it's in Wootton Bassett but it's not about the people there and it's not against them personally - rather it's to highlight the real cost of war in Afghanistan.
"The sad reality of the situation is that if I were to hold it somewhere else it would not have the media attention that it has now."
A date has not been set for the demonstration but Mr Choudary said it was "full steam ahead" for the campaign for the withdrawal of British troops.