Any attempt to distress the families of dead soldiers would be abhorrent and offensive, he said in a statement.
Home Secretary Alan Johnson said the proposed march through Wootton Bassett in southwest England filled him with revulsion and he would grant a ban on the march on public order grounds if police and the local authority sought one.
Mourners regularly line the streets of Wootton Bassett as the coffins of troops pass through the town from a nearby airforce base which receives the bodies of British soldiers flown back from Afghanistan.
Islamist activist Anjem Choudary said his organization Islam4UK intended to hold the procession to highlight the deaths of innocent Muslim men, women and children who had been killed in the conflict.
Islam4UK seeks the introduction of sharia law in Britain has links to Islmaist militant leader Omar Bakri Mohammed who has been banned from entering Britain. The group's website gave no indication of when the march would take place.
Some 246 British soldiers have been killed in Afghanistan since the invasion to oust the Taliban in 2001.
A protest last March by Choudary's supporters in Luton, north of London, against soldiers returning from Iraq led to widespread condemnation.
A facebook page set up to oppose the Wootton Bassett procession has already attracted almost 180,000 supporters.
(Reporting by Michael Holden and Tim Castle; Editing by Jon Hemming)