The suggestion that the IRA has completely disarmed is a "blatant lie", DUP leader Ian Paisley has said.
Mr Paisley made the comments to his party conference in Belfast
He told his party's conference there would be no executive with Sinn Fein as long as the IRA was "in business".
Mr Paisley said the fall-out from the Independent Monitoring Commission report last week had "justified" their scepticism about the IRA.
But Sinn Fein's Gerry Adams said the political context had changed and his party stood ready to work with the DUP.
The Independent Monitoring Commission said on Wednesday that it had received reports that the IRA held on to some of its weapons - after a final act of decommissioning last September.
It said these were possibly for personal protection or area protection.
However, General de Chastelain, said there was no indication that the "quantities of arms involved were substantial".
Mr Paisley told his party conference on Saturday: "When I look back over the last month, I see the mighty host of forces intent on pushing down the throats of the Ulster people the blatant lie that the IRA has decommissioned all its weapons.
"That falsehood was so blatant even Lord Haw-Haw would have blushed to utter it."
He claimed General John de Chastelain, the head of the arms body, had been "misinformed".
The IMC report was into paramilitary activity
Mr Paisley said the British and Irish governments had to play their part in the political process by delivering fairness and equality to unionists.
"The message must be crystal clear. The IRA must be packed off for good," he said.
However, Sinn Fein President Gerry Adams called for an end to the "rhetoric"
surrounding the political process and said devolution had to be restored within a
In an address to the national conference of Ogra Shinn Fein (Sinn Fein Youth) in Dublin, he said: "This party stands ready to work with the DUP.
"We do so already in councils
across the north and we did in the assembly when it functioned.
"Each day British direct rule ministers take decisions on spending reviews,
health, education, the environment, energy and other matters which adversely
effect every citizen in the north and have a knock-on effect throughout the
"The DUP's refusal to work with Sinn Fein in government is allowing this to
Earlier, DUP deputy leader Peter Robinson said the DUP would withdraw from the Policing Board if Sinn Fein took places on it in the near future.
The board is due to be re-appointed with new members in April and two places will be reserved for Sinn Fein.
Sinn Fein, however, said it would not consider joining until policing powers were devolved to local politicians.
Mr Robinson said Sinn Fein participation would "undermine the board".
The British and Irish governments will launch a fresh round of talks with the political parties on Monday in a bid to restore devolved government to Northern Ireland.
Sinn Fein has been demanding more reforms to policing and has called for policing and justice powers to be transferred from Westminster to Stormont.
The party has refused to recommend the Police Service of Northern Ireland as a career for young Catholics or take its seats on the Policing Board which holds the force to account.