As unionist calls for Sinn Fein's dismissal form the Northern Executive continue this evening, the party's health minister Bairbre de Brun urged UUP cabinet colleagues not to pull down the administration.
Standing outside Andersonstown police station in west Belfast in one of six lunchtime protests organised by Republicans against the arrests of the four people, she accused police of engaging in "theatre" to blacken the name of her party.
The West Belfast MLA insisted: "I think the executive needs to survive this.
"I can't personally, single-handedly, make it survive but I have to say to everybody else who is involved I am totally and utterly committed, as is my party, to this peace process.
"We are committed to forward movement, to working with others, and to working with everybody - former opponents, former opponents that a lot of people would not have expected us to be willing to work with."
Republican sources described Sinn Fein officials as being "incandescent" at the allegations being levelled at their party.
Ulster Unionist sources indicated that much was riding on next week's meeting between their leader, Mr David Trimble, and Prime Minister Tony Blair.
A party source said: "David is really under pressure ... If Mr Blair doesn't move, we have to make it clear that we will go for the nuclear option."
Mr Donaldson tonight reiterated that point of view.
"Let's be clear, if the Prime Minister fails to take action to remove Sinn Fein from the government of Northern Ireland this week, then we will have to move to take that action."
Mr Donaldson claimed Sinn Fein was "on the back foot" over yesterday's arrests and raids.
He said that the hysterical reaction of Sinn Fein Assembly member Gerry Kelly was the reaction of a man whose movement had been "found out, had been exposed".
"Where are Adams and McGuinness?
"Why have they gone silent? Why the silence?
"I think we know. The silence betrays their guilt.
"Sinn Fein are on the back foot here and you can see that in the reaction of them yesterday and the silence of Adams and McGuinness."
PA