Ian Paisley has demanded that Sinn Fein state clearly that it will support the PSNI police and encourage its community to work with the PSNI before it will agree to share power with Sinn Fein.
The Dublin and London government are to present a paper outlining their plan for how to advance the peace process ahead of the final day of intensive talks at St Andrews in Scotland.
Talks are deadlocked with Ian Paisley adamant that Sinn Fein would first have to declare their acceptance of the PSNI, a British constabulary in the Six Counties.
"We are not putting before them an ultimatum from the DUP, from unionists," the North Antrim MP said. "We are putting before them an ultimatum for democrats."
"Those who want to serve in the government of a democracy must totally and absolutely support the police at every level and must be seen to be supporting the police."
In a rhetorical tirade to reporters, he continued: "Why should you be special? Why do you insist on making support for the police a bargaining chip? We are not going to bargain on that. It is not up for grabs. You have to do it."
Sinn Fein chief negotiator, Martin McGuinness, said the DUP leader had to play his part in resolving the policing issue.
"Ian Paisley has to recognise that the argument we have made, for some considerable time, that powers be transferred to a locally elected and accountable administration, that that must happen," the Mid-Ulster MP said.
"It cannot happen without his support. "I suppose in many ways to put it simply we need his help.
"He needs our help and we are certainly willing to help him but what I want to see in the coming hours as we move to the completion of these talks tomorrow is Ian Paisley recognising the importance of helping us with the issues that we need help on.
"We certainly need the institutions restored. We need to agree, for example, the shape of the department which will deal with justice and policing and we need a time frame for the transfer of powers."