Senator Sherwin Gatchalian on Wednesday disagreed with Budget Secretary Benjamin Diokno's claim that the government cannot shoulder the cost of the proposed free tuition in state universities and colleges (SUCs).

"(Diokno's) figure is way off the mark," Gatchalian, Senate Committee on Education vice chairman, said in a statement.

Diokno earlier said the free tertiary education program will cost the government P100 billion annually.

The cost of subsidizing tuition in public technical-vocational institutions, and state universities and colleges is approximately P30 billion, Gatchalian said.

"Certainly, the government can afford to make this investment for the benefit of millions of young Filipinos," he said.

Socioeconomic and Planning Secretary Ernesto Pernia's conclusion that subsidizing tuition in state universities and colleges would have minimal impact is also wrong, Gatchalian, an administration ally, said.

"By lessening the burden of educational costs on working-class households, we are giving them the chance to build a secure and happy future for themselves and their families," Gatchlian said.

"This is in line with the country's long-term socioeconomic goal of building a strong middle-income society," he added.

President Rodrigo Duterte has yet to sign into law the legislative measure that would guarantee free tuition in state universities and colleges.

"I will decide before the deadline," Duterte told reporters at the sidelines of the Bureau of Internal Revenue's anniversary celebration in Quezon City.