Mr Jeffrey Donaldson and his fellow dissident Ulster Unionist MPs were last night seeking legal advice to determine if they could overturn a decision to suspend them from the party.
Mr Donaldson said he was "astounded" by yesterday's decision of the UUP disciplinary committee set up at the request of Mr David Trimble to suspend him from the party along with MPs Mr David Burnside and the Rev Martin Smyth.
The party's officer board established the committee on Thursday to consider a charge that the three MPs in resigning the Westminster whip, and in refusing to obey party policy on the joint declaration as endorsed by the Ulster Unionist Council, were acting in a fashion detrimental to Ulster Unionism.
On Thursday, Mr Trimble expressed the hope that "in view of the prominence of the issue" the case should be dealt with speedily. Few, however, expected that suspension would take place before the three MPs put their defence to the committee.
Sources for both sides said there could be no retreat now from a "battle to the death". As a mark of the depth of bitterness, Mr Donaldson compared the action to IRA "summary justice".
"In the past we have pointed the finger at others including the IRA and accused them of engaging in kangaroo courts and summary justice. Where is the justice in this process?" he told The Irish Times.
"We as a party uphold the rule of law, we support British justice. No hearing? No opportunity to put our case before disciplinary action is taken? That is summary justice in anyone's book," added Mr Donaldson.
This week for the first time Mr Trimble indicated that there would be no shirking or fudging this battle with Mr Donaldson and the anti-Belfast Agreement wing of the party.
His supporters believe that this action by the disciplinary committee reflects that determination. Mr Trimble said on Thursday that the party could no longer tolerate a "party within a party".
The three MPs are suspended but can address the disciplinary committee chaired by Enniskillen solicitor Mr Raymond Ferguson on July 17th. According to the committee's statement: "Under the party rules, anyone suspended from membership ceases to be a member and forfeits all the rights and privileges of party membership." Mr Donaldson said yesterday that Mr Trimble "has made no secret of his desire that we should be removed from the party".
Mr Donaldson added that the suspension was in clear contravention of the rules of the party which, he added, dictated that disciplinary measures could only be taken after those charged had put their defence.
With Mr Smyth and Mr Burnside he was now seeking legal advice to test whether the suspension could be challenged. Mr Burnside described the suspension as "contemptible" and said the UUP leadership was "committing political suicide". Mr Smyth said the decision was contrary to "natural justice".