More than 1,000 people are expected to take part in a parade to remember the victims of the explosion at Royal Avenue on 24 February 1988.
UDR men James Cummings and Fred Starrett died when the booby-trap bomb detonated behind hoardings as Castle Court was being built.
The fatal attack is marked every year, but the forthcoming anniversary could coincide with protests which have been held each Saturday since December, when crowds gather outside Belfast City Hall to protest against the decision to limit the flying of the Union flag.
A former security force colleague of the 1988 victims told U105 that this Saturday should be used solely to remember those killed in the IRA bomb.
"I was there, caught up in the explosion, and those two young men were killed," he explained.
"I'm saying to [Jamie] Bryson and these other ones, I don't know where you're coming from, but at the end of the day, the flag protests aren't going to get you anywhere."
I would prefer, as a guy who was involved in the explosion, to cancel the flag protests completely and all go down to commemorate the two guys.
Former UDR soldier
His request was echoed by DUP leader and First Minister Peter Robinson and UUP leader Mike Nesbitt, who said the spotlight should be placed on the victims of the fatal bomb attack.
Mr Robinson said that protestors may see "the real benefit of putting the focus on the death of two soldiers at the hands of the IRA".
He added: "It's an event that comes once a year and I would have thought that they would have added very considerable respect for their cause if they were to give way, to have the focus on that one event during the course of Saturday.
"I hope that they will take that advice."
Ulster Unionist leader Mike Nesbitt said: "Nothing should deflect from marking the memory of these two brave citizens of Northern Ireland.
"Given the cost of the flags protests, it would be regrettable if those involved did not take the opportunity to step back to allow the media to highlight how republicans once stopped at nothing to pursue their economic war against Northern Ireland, irrespective of the cost in terms of human lives or impact on the economy.
"The cost of the current protests cannot be justified, but are as nothing to the equally unjustifiable cost of the Troubles."
The Strangford MLA appealed to loyalist representatives, including Jamie Bryson of the Ulster People's Forum, to use their influence to call off the protest.
"I further call, as I have since the first week of December last, for the flags protests to move off the streets," Mr Nesbitt added.
"It is clear to all that the issues go far beyond the Union Flag, and I repeat my invitation to Mr Bryson and his colleagues to engage with the Unionist Forum, which offers a unique opportunity to air their grievances with the realistic hope of redress."