Prime Minister Giulio Andreotti is expected to face a political crisis when he returns from Washington on Monday, and political commentators say the collapse of his 21-month-old coalition government appears unavoidable.

At the center of the drama is President Francesco Cossiga, the 62-year-old head of state, who has embarked on a campaign to end what he says is a longstanding attack on his personal dignity and his office as president of the republic.In television interviews Friday and Saturday, Cossiga, a Christian Democrat and twice prime minister, declined to confirm reports that he would ask Andreotti to resign.

Andreotti refused to discuss the situation in Paris and went ahead with his trip to New York for talks with U.N. Secretary-General Javier Perez de Cuellar. Sunday, Andreotti is scheduled to meet President Bush in the White House.