The government has made a secret deal with the IRA to exclude the need for an arms witness acceptable to unionists, DUP leader Ian Paisley has claimed.
Ian Paisley said they were raising concerns now rather than later
He was speaking after meeting Political Development Minister David Hanson about DUP concerns over IRA decommissioning.
Mr Paisley said the process was a mess, that the IRA made the rules, appointed the referee and was doing as it wanted.
Sinn Fein leader Gerry Adams said if the DUP wanted to nominate a witness it should have talked to his party.
"It's a bit rich when unionist paramilitaries are using heavy calibre shoulder weapons to shoot at British troops and PSNI officers, and profess to be loyalists, that the DUP would be concerned about IRA weapons which are silenced and, which we all hope and pray, are going to be put beyond use in the period ahead," he said.
Mr Adams also said that whilst the IRA killers of Garda Jerry McCabe had taken themselves out of any political deal, Sinn Fein still regarded them as prisoners who should qualify for early release.
Mr Paisley said the DUP had sought the meeting with Mr Hanson now so they could not be accused of raising their concerns too late.
"We warned the minister, don't come afterwards and say, 'Why is Ian Paisley raising this?' We're raising it now," he said.
It is understood former Presbyterian Church moderator David McGaughey was asked by the DUP last December to be the Protestant witness to IRA decommissioning.
However, the IRA has the final say and the DUP has concerns this will mean the process will be unacceptable to unionists.
The DUP's meeting with Mr Hanson came as the minister told the BBC's Hearts and Minds programme that the IRA was beginning to make moves related to decommissioning.
David Hanson: "We have obviously to have that verified"
The minister said it would be up to unionists to take up the challenge if the IRA's actions were verified.
"I think the IRA are beginning, following the statement, to make those moves," said Mr Hanson.
"We have obviously to have that verified. We have to look at the decommissioning.
"A range of individuals have to look at it - the monitoring commission and a whole range of people.
"If we come back to the situation whereby early in the new year we verify that, we monitor it, we see that the deeds they have said are actually monitored and undertaken with actions on the ground, then I think the challenge is there for the unionist community to say whether they trust that process."
Mr Hanson's new role was announced by Northern Ireland Secretary Peter Hain on Wednesday.
He is to take charge of a new plan to co-ordinate efforts in loyalist areas, involving intensive talks with elected representatives and civil leaders from the Protestant community.
Mr Hanson said he would tackle deprivation in loyalist working class areas without rewarding recent violence.
His other portfolios cover political affairs and social development.
In his television interview, Mr Hanson confirmed that the government was considering holding another economic conference to address the need for investment in Northern Ireland.
He also discussed the "opportunity" created by the IRA initiative in late July, when it formally ordered an end to its armed campaign.
BBC NI political editor Mark Devenport said: "Government ministers have been trying to sidestep this and just saying they hope this will happen.
"Peter Hain's terminology was 'sooner rather than later'. At the same time there have been lots of rumours that John de Chastelain's decommissioning body is at its work, even though it has not been giving a running commentary.
"That means the destruction of weapons is under way or some sort of preparatory move - the movement of weapons towards dumps where they will be destroyed.
"The whole political process is contingent on this happening."