Tensions over the flying of the Union flag in Belfast were whipped up by unionist parties to win votes, the leader of the Alliance Party claimed.
David Ford alleged protests against his colleagues were part of a "project" to damage the party.
East Belfast MP Naomi Long's office has been targeted by demonstrators and premises in Carrickfergus in Co Antrim burned after the party voted for flag change in the city.
Mr Ford told his party's annual conference in Co Down there should be a united voice supporting the rule of law.
"There is only one conclusion, in Belfast there was a deliberate, pre-meditated campaign to whip up tensions, to generate fears over loss of identity among those who perceive themselves as having little left to give and to go after the Alliance Party and it's elected representatives, especially Naomi Long who wasn't even involved in the debate, in order to win votes," he said.
Weeks of loyalist protest have followed Belfast City Council`s decision to restrict the flying of the emblem from City Hall to designated days like Royal holidays, rather than every day of the year.
The change was enabled by Alliance's casting vote, which it argued left Belfast no different from many other civic buildings across the UK.
Leaflets were circulated by the DUP and UUP before the December 3 vote highlighting the issue.
Protests outside the City Hall turned violent and almost 150 police officers have been injured during weeks of demonstrations since then. The DUP and UUP have called for an end to protests, which also caused commuter chaos.
Mr Ford accused unionists of using weasel words after a football match was disrupted at Seaview in North Belfast by protesters recently and claimed nationalists were trying to put pressure on the police, and added: "There ought to be a united voice supporting the rule of law from every party. Ought to be but I doubt it."