Organisors said they never intended to offend veterans
A group of World War II veterans say a march in Cardiff on Armed Forces Day will go too fast for them to keep up.
The march from the castle to Cardiff Bay on 26 June will take place at 116 paces per minute.
Veterans from Treorchy, Rhondda Cynon Taf, say a letter stating that those who fall behind will not be able to rejoin the parade is "insulting".
But organisers say they have arranged for veterans to march a smaller route at a slower pace.
Veteran Des Powell said the 'no slacking' letter was 'insulting'
The Treorchy Royal British Legion veterans said last year's event saw them lagging up to 300 yards behind the main march and they were left "collapsing" afterwards.
They have said they will not be marching at the planned Armed Forces Day in Cardiff next month as they are worried they will not be able to keep up the pace.
Des Powell, 83, said: "The whole context of the letter was insulting to everyone - to say "there will be no slacking". We won't be marching.
"The distance of the march is another thing that's stupid. It's really crazy. They are treating people as basic machines."
Dave Morris, the main coordinator for Armed Forces Day in south Wales, said there was no intention to insult the veterans.
He said the length of the parade had been decided by Ministry of Defence. "If it had been our decision, we would not be marching from the castle," he said.
"We, the veterans' committee, have from the outset said that this march is far too long for the veterans.
"The letter was intended to inform the veterans who are thinking of taking part in the parade what is involved."
He said the "young and fit" uniformed troops would be marching at a regulation pace throughout and if others in the parade fell behind it would "look like the retreat from Moscow".
The veterans were being given the option to take part in the whole march but had to be sure the were fit enough to maintain that pace, he said.
Mr Morris said this was why the organisers had arranged for a "step-in point" where veterans could join the march within 500 yards of Roald Dahl Plas and continue at a pace to suit them.
Mr Morris added that he was sorry to learn the letter had caused offence.
He said: "That was not the intention of the letter. I'm a veteran. I would never insult the veterans."