Reverend Ian Paisley is to protest during the Pope's UK visit this week.
The North's former First Minister says he will act as a "champion" for the victims of sex abuse by Catholic priests.
Reverand Paisley said he decided to mount the protest during the Scottish leg of Pope Benedict XVI's tour because he had been contacted by "many Roman Catholic people who were troubled by the actions of Rome" in regard to the abuse of children.
A delegation from Paisley's Free Presbyterian Church will travel to Scotland from the North and hold a rally at a church in Rutherglen near Glasgow on Wednesday evening.
The church said it is opposed to the papal visit on “financial, constitutional and moral grounds”.
On Thursday the group, including founder the Rev Paisley, now Lord Bannside, will hold a service in Edinburgh’s Magdalen Chapel followed by a public protest in the Grassmarket.