Nicaragua's internal dialogue stalls over opposition call for reforms. Managua says demands coincide with US plans to topple Nicaraguan government

The Nicaraguan government's relations with opposition parties have plunged to a new low in recent days, threatening the hopes of national reconciliation and democracy held out by Central America's peace accord. Fourteen opposition groups from both left and right suspended their 10-week dialogue with the Sandinista government after it refused to accept major reforms to the Constitution the groups consider essential to a democratic system.

This followed a speech by Defense Minister Humberto Ortega Saavedra over the weekend in which he threatened harsh reprisals against opponents who ``go beyond the framework this popular revolution has allowed.''

Meanwhile, the government announced yesterday a two-day Christmas truce and the resumption of peace talks with the contra rebels next week in the Dominican Republic.

The national dialogue has run aground on the opposition's insistence that the Sandinistas agree to 17 reforms to the Constitution. The National Assembly approved the Constitution last year. That charter, Nicaraguan Socialist Party leader Lu'is S'anchez said Tuesday, ``suffers from a series of insufficiencies.''

The opposition parties are demanding, among other things, that the President's powers be limited and that he not be allowed to stand for re-election; that military personnel not be allowed to vote; and that the Constitution draw clear lines between the Army, the ruling party, and the state.

They are also demanding reforms to the electoral tribunal to ensure its impartiality, and guarantees of the judiciary's independence.

Sandinista comandante Carlos Nunez, representing the government in the national dialogue, refused to agree to these reforms, arguing that only the National Assembly is empowered to change the Constitution. But his suggestion that the draft reforms be submitted to the assembly for consideration met with little sympathy among opposition leaders. The Sandinista Front holds 61 of the assembly's 96 seats.

The government is prepared to discuss specific electoral issues, such as a new law for municipalities due to chose local authorities next year. But the opposition says laws drawn up under a flawed Constitution would themselves be flawed.

The Sandinistas seem unlikely to yield on this question, after spending two years on nationwide consultations about the Constitution and basing much of their legitimacy in power on the document.

Indeed, the demands for reform have provoked an unusually fierce response from Sandinista leaders. Gen. Humberto Ortega argued in a speech Saturday to Sandinista trade unionists that left-wing and right-wing parties are making ``the same demands against the Sandinista revolution and coinciding totally with Reagan's plan against Nicaragua.

``We are not just watching passively a series of attitudes of these sectors of the right ... who in practice are acting as the clearest complement of Reagan's mercenary destabilization plan, falling into seditious and subversive attitudes,'' Ortega warned.

A day later, the general's brother, President Daniel Ortega Saavedra, echoed the theme. ``A revolutionary power has been built here, a workers' power which gives space for political participation to its class enemies. That space can perfectly well be closed off by the working masses of our country,'' he threatened.

These strong words, which surprised Western diplomats here, came as a Nicaraguan Army defector in Washington publicized Nicaraguan plans for a Soviet-supported military buildup, and alleged that General Ortega had misappropriated military funds. Former Nicaraguan Army Maj. Roger Miranda Bengoechea had been General Ortega's closest aide, and his defection was seen as a major personal and political blow to the defense minister.

Predicting that the US administration would use Major Miranda's revelations as fuel in its bid to win continued congressional funding for the contras, President Ortega issued a thinly veiled warning to his domestic opponents not to make too much of the defector's statements.

``There's a Chile-style plan for Nicaragua, aimed at ... destabilizing the country internally,'' he claimed, referring to the US's campaign to destabilize President Salvador Allende's government in Chile, toppled by a 1973 military coup.

General Ortega also referred to this alleged plan, accusing the US of maintaining the contras while using the internal opposition to stir up popular discontent with the government in preparation for an invasion. ``We are not going to give them the chance,'' he warned bluntly.