Lech Walesa, leader of the banned Solidarity labor movement, was ordered today by a government prosecutor to report to authorities each time he wants to leave his hometown, Gdansk, because of an investigation against him on charges of organizing illegal protests and inciting unrest.

But Walesa said the warning would not affect him. "They will have no problem finding me because my observers are watching me day and night," he told reporters, referring to his round-the-clock police surveillance.

After answering a summons to the prosecutor's office in Gdansk, Walesa said he had refused to answer questions and instead had delivered a written protest against attacks on Solidarity and the jailing of three leading opposition activists last month.

The restriction order represented the first time since Walesa's release from detention in November 1982 that authorities had slapped such a constraint on him, but the move appeared to be little more than a form of further harassment by Communist officials, who are reluctant to prosecute the Nobel Peace Prize winner.

Meanwhile, Solidarity's main underground committee called for demonstrations May 1 demanding the release of political prisoners and wage raises to compensate for food and energy price increases.

The underground leaders claimed their last protest call -- for a 15-minute strike at noon Feb. 28 -- had been responsible for a government decision to modify proposed price increases.

Rather than impose across-the-board increases this month as originally planned, the government said last week that it would spread increases over four months. It said the change was being made in response to complaints from the official trade unions, not from Solidarity. Walesa then canceled the strike call for Feb. 28.

The first price rises took effect Monday, on bread, flour, cooking oil, rice and some dairy products.

The underground statement charged that past price increases have failed to improve Poland's bankrupt economy and it demanded a 12 percent rise in salaries to compensate for the price increases.

Solidarity supporters were urged to hold rallies on April 1, when phase two of price increases is due.

Today was the second time Walesa has been called before investigators since police broke up a Feb. 13 meeting in Gdansk of opposition activists that Walesa has said he organized to discuss the current situation. Walesa was released, but three other dissidents -- historian Adam Michnik and Solidarity leaders Wladyslaw Frasyniuk of Wroclaw and Bogdan Lis of Gdansk -- were jailed and are still being held on charges of illegal union activity. Walesa told the prosecutor the charges against him and his colleagues were groundless and violated constitutional guarantees.

The police action against Walesa and the others coincides with moves to break links between opposition activists here and abroad.