A crucial phase in Anglo-Irish relations has begun following the signing here Nov. 15 of an agreement on Northern Ireland between London and Dublin. Leaders of Unionists, or those who favor maintaining Northern Ireland's status as a province of Britain, plan to challenge the British government on the legality of the agreement in Northern Ireland's highest court. Also, the Unionists have called a protest rally for Sunday.
Unionists say the agreement, which gives Ireland a formal say in the running of the province, infringes on the right of people of Northern Ireland to be treated the same as other British citizens.
Unionist reaction has been swift and predictable. Peter Robinson, deputy leader of the hard-line Democratic Unionist Party, at the weekend, denounced British Prime Minister Margaret Thatcher during an emergency debate in the Northern Ireland Assembly, as ``an unprincipled, shameless hussy.''
Such strident language, observers here say, will not help the hard-liners' cause, nor will it deflect Mrs. Thatcher, who is determined to make the agreement work. Significantly, however, there is growing opposition to the agreement from Protestants who would not normally back the more controversial politicians.
Moderate Unionists, who are neither anti-Roman Catholic nor anti-Dublin, say they do not like either the large or small print of the accord.
``The prime minister asked us to read the agreement carefully before jumping to conclusions,'' said one Protestant. ``I have done that, and the more I read the agreement, the more worried I become.''
Protestants are worried because the agreement was reached without consultations with their representatives and because the Dublin government now has direct access to the policymakers who run Northern Ireland. They are not convinced that the agreement will lessen terrorism.
``I would pay the price if the agreement helped to bring peace, but I cannot honestly see it happening that way,'' said a moderate Unionist.
Protestants point out that while the agreement is supported by the British and Irish governments, the European Community, and the United States, it is opposed by the Protestant majority in Northern Ireland, by the majority party in the Irish Republic, and both the outlawed Irish Republican Army and the loyalist paramilitaries, such as the Ulster Defense Association.
The Belfast Telegraph, which has long championed moderate unionism, stated bluntly that ``relations between the United Kingdom and the Republic of Ireland have changed fundamentally. A part of the United Kingdom will be run in consultation with the government of another state.''
This, in essence, is the heart of Protestants' fears. Despite joint assurances from London and Dublin that Northern Ireland will remain part of the United Kingdom as long as the majority wishes, Protestant citizens feel a little less British today. One analyst here suggests that it is as if a citizen of the US were asked to accept direct Canadian or Mexican consultative input into how the US is ruled.
Ironically, there is less fear, as yet, of street violence. Downtown Belfast is a rejuvenated city with an active night life and a shopping center that attracts thousands of bargain hunters from the Irish Republic. But the broad spectrum of Protestant opinion is that a significant agreement about their future has been signed without their consent.
Some experts predict growing support for constitutional and legal protests led by Unionist politicians. There is also the danger that the paramilitaries will attempt further atrocities.
The Belfast Telegraph summed up the position concisely in its front-page headline: ``Agreement signed -- but consent does not exist.''