Published Tuesday, 15 October 2013
On Tuesday Michelle Williamson, who lost her mother Gillian and father George in the blast, said a plan to unveil a plaque to Begley on Sunday is a "cruel insult to the memory of lost loved ones".
She was joined by victim campaigner Willie Frazer to present a letter to the Antrim Road Sinn Féin office in north Belfast.
She wrote in the letter that she "didn't blame you or your family in any way for your son's actions" and asked the parents to call on publicly on Sinn Féin and those involved in the community to cancel the event.
"The IRA wrecked both our families that day, don't let them hurt us again," she said.
Nine civilians, including two children, were killed in the blast at the shop in October 1993. Begley was also killed when the bomb exploded prematurely.
The IRA said the intended target was a flat above the shop where loyalist paramilitaries were expected to gather, but the meeting did not go ahead.
Previously North Belfast MLA Gerry Kelly said family and friends had the right to mark the death.
But at the weekend, it emerged that Begley's parents would have preferred a private family memorial and didn't necessarily want a plaque to be erected.
In a statement, Sinn Féin described Ms Williamson and Mr Frazer's visit as a "media stunt".
"The family and friends of Thomas Begley will remember him with dignity and respect. They have no intention of offending anyone," a spokesperson said.
They added that the commemoration "is not being organised by Sinn Féin."
Meanwhile, a memorial committee on the Shankill Road is also finalising plans for how the local community will mark the date.
© UTV News