Uruguay's most famous exile rattles Army in river voyage home

Officially, Uruguay is to have its first presidential elections in 13 years this November. And next March the military regime is scheduled to hand power to the elected civilian authorities.

But unofficially, the timetable is beginning to look overly ambitious in the midst of a climate of growing confrontation between hard-line military officers and the civilian opposition.

The main source of tension is Wilson Ferreira Aldunate, Uruguay's most famous political exile, who won more votes than any other presidential candidate in Uruguayan history in the country's last free elections in 1971.

Speaking to The Christian Science Monitor Wednesday, Wilson, as he is known to friends and foes alike, confirmed that he plans to return to Uruguay tomorrow after crossing the River Plate in an overnight ferry filled with a few supporters and more than 200 journalists.

When he lands on the other side of the river, the charismatic center-left leader of the Blanco Party expects to meet thousands of supporters and sympathizers who plan to converge on Montevideo from all over the country. Farm workers on tractors, gauchos on horseback, students, trade unionists, Uruguayans of all professions reportedly plan to greet Wilson for what promises to be as one of the biggest rallies in Uruguayan history.

The military, however, is planning a very different reception. Over the last couple of months the government has done everything in its power to make sure that Uruguayans do not hear about Wilson. Twelve newspapers have either been closed or had their issues confiscated for reproducing reports about Wilson.

This week the clampdown was extended to cover all news media coverage of his arrival and a blanket ban was placed on political rallies. In announcing these actions, the government warned that ''professional agitators'' had illegally entered the country with explosives to provoke the security forces and claim ''martyrs.''

Uruguay's military has felt the effects of Wilson activity even though he was not in the country. Opposition to the government has been growing in response to President, Gen. Gregorio Alvarez's plans for a ''controlled'' democracy. Under his plan, the military will hand over power to the civilians in March 1985, but only on the condition that the armed forces are given participation in the government and the legal system. All politicians who object to this have been banned from political activity.

''The next 60 days in Uruguay are going to be crucial. The military have to decide whether they want real democracy or a farce,'' says Wilson.

Although Wilson won more votes than any candidate in the 1971 election, he was did not become president because the more middle-of-the-road Colorado Party fielded a dozen candidates and won final victory with their total votes.

When he went into exile after the military takeover in 1973, Wilson's stature grew through his defense of human rights and his unrelenting opposition to any military attempt dictate the terms of the transition to democracy.

This spring Wilson moved from his temporary home in Europe and arrived in neighboring Argentina as a guest of the democratic government of Raul Alfonsin: It was, he said, the ''final stage'' before his definite return.

The regime is understood to be split between ''moderates'' who fear that imprisoning Wilson after his return would unleash political violence, and ''hard-liners'' who believe that Wilson is a destablizing factor anyway and want to see him out of the way and behind bars as soon as possible.

Wilson denies the military's charge that he is bent on provoking a confrontation and destabilizing the regime. ''I believe that the best way to insure democracy is through dialogue. I'm going back now because I think the time is right - the military is weak and the opposition is strong. . . . But in what country in the world can you make democracy a reality if the most important political figure is in exile or in jail?''

Wilson's program threatens a radical U-turn in economic policy if he comes to power: He promises substantial agrarian reform, greater control in the local banking system - the most liberal in South America - and a tougher stance on the country's $4.2 billion foreign debt.