Help us find Disappeared before retiring, Adams urged
Gerry Adams has been urged to use his remaining time as Sinn Fein president to produce information that could lead to the recovery of the last Disappeared.
Ulster Unionist leader Robin Swann said the disclosure of any information could bring "closure" for the families of victims whose bodies have never been found.
Mr Swann's call came amid speculation that Mr Adams will make a significant announcement on his future at the party's ard fheis this evening.
Three of 16 people murdered and secretly buried by republican paramilitaries during the Troubles remain missing.
The remains of Columba McVeigh, Joe Lynskey and Army captain Robert Nairac have yet to be discovered.
Mr Swann said: "If we are to believe media reports, this weekend is likely to see Gerry Adams set out his plans for stepping down as president of Sinn Fein.
"Before he does, I would ask him to tell the republican movement to hand over any information it has in relation to the remaining Disappeared - Captain Robert Nairac, Columba McVeigh and Joe Lynskey.
"All these men deserve a Christian burial. They were robbed of life and their families have suffered ever since, with some of their nearest and dearest not living to see this terrible wrong righted.
"As Sinn Fein makes calls for dignity and respect, let Saturday see them show respect to the families that still are without the closure that comes with the dignity of being able to lay a loved one to rest.
"And indeed, to the thousands of families who want to know why their loved ones were murdered and maimed by the IRA.
"Gerry Adams is one remaining person who has the authority within the republican movement to end the nightmare for a lot of families.
"He has a window of opportunity to demonstrate some human compassion. I would appeal for him to take it."
Sinn Fein declined to make a comment on Mr Swann's intervention.