Mr Gerry Adams has come under attack from the Democratic Unionist Party over his call for a ban on "provocative" Orange marches.
Warning of a "major crisis" in the coming weeks, the Sinn Fein leader said the expectation among nationalists was that contentious parades should be prohibited and nationalist rights upheld.
However, Mr Nigel Dodds of the DUP accused Mr Adams of deliberately fuelling tension, especially over the Tour of the North parade planned for north Belfast on June 19th.
Mr Glyn Roberts of the Alliance Party called for dialogue between the marchers and nationalist residents of north Belfast.
The Sinn Fein leader issued his call for a parades ban at a news conference in Belfast. He said the "relatively small number of contentious marches" was becoming an acid test of the British government's commitment to change the status quo.
He wondered if the "Orange Card" would triumph again.
"There is a head of steam building up around the so-called Tour of the North - an Orange march in north Belfast which passes through nationalist areas. To date there has been no official or serious effort to broker an accommodation. This is a matter of very, very deep concern," he said.
He had raised these matters in what he called a "crisis meeting" with the Taoiseach, Mr Ahern, last week and had also discussed them with the British Prime Minister, Mr Blair, and with President Clinton.
He said there was a "huge onus" on Mr David Trimble to help defuse the parades crisis.
"There are thousands of parades each year and Sinn Fein has consistently upheld the rights of the marching orders. That a small number of contentious parades are ignoring the wishes of the vast majority of people, or that those involved refuse to even talk to their neighbours, is a disgrace," Mr Adams said.
Mr Dodds of the DUP said: "This pot-stirring by Adams is a deliberate but patently transparent ploy to create an expectation of trouble from nationalists which, if it materialises, will be nothing more than a self-fulfilling prophecy on the part of the republican leadership.
"The Tour of the North should be allowed to proceed as normal and the sabre-rattling by Gerry Adams and his friends should be ignored."
Mr Roberts said: "The negative attitude of the Orange Order has not been helpful . . . Their refusal to meet with myself is nothing less than ridiculous and they should urgently reconsider a meeting so that a constructive exchange of views can take place.
"I am frankly amazed that they will not meet with me as I have always been committed to resolution of disputes by peaceful and political means and totally oppose all violence."
Meanwhile the Ulster Unionist Party leader, Mr Trimble, has predicted it will be well into next year before a government for Northern Ireland, based on the Assembly, is set up.
"We don't have the legislation," he told The Irish Times. "I know from the government that it is looking at the transfer of functions in February next, and that might even slip back.
"The ministries, the number of ministries and what they should be, will have to be negotiated between the parties." On decommissioning, he said the British Prime Minister had told him in April that in his view decommissioning should start immediately.
"The two-year time-span is running from the referendum in May. Mr Blair said that if, in the first six months, things were not being done as they should be, there would be changes in the legislation."