Manuel Ray, former Minister of Public Works under Castro, yesterday described his efforts to undo the "destructive revolution" in Cuba and to promote peaceful reform elsewhere in Latin America.

He told the Latin American Association that Castro's support has dwindled to less than five per cent of the Cuban people, and that most of his backers are former Batistites. Ray predicted that internal opposition to Castro would become active within two or three months.

"Castro's early supporters feel that they must start fighting again," he said, "in order to defeat a man who seeks power merely for the pleasure of using it against others."

In order to prevent more revolutions of the Cuban variety, Latin America's enormous social problems, such as the housing shortage, must be quickly solved, Ray said. Forty million Latin Americans are homeless now and the situation is worsening every year, he added.

Since leaving Cuba, Ray has worked for the Puerto Rican Planning Board, designing low-cost mass housing for rural and suburban areas. He hopes to convince Latin Americans to increase public and private investment in housing and to divert more foreign aid funds to the solution of the problem.

Ray has devised a six-room house made of pre-cast concrete which costs less than $1300. The structure was designed for use in "self-help and mutual assistance programs," and can be assembled by eight unskilled workers in eight days