Speaking at the main 71st National Day function in Colombo, he questioned if it would be ethical to form a national government with a party having just one MP.
The cabinet should be confined to 25 members, he said.
The national government previously made many achievements, he said, adding that what should not have been done, had been done.
In the post-war period, people were most free in the past four years, according to him.
He also said political leaders had failed to bring about economic development.
People are not prepared for a slow economic growth any more, he said.
Education should be transformed to suit the 21st century in order to gain economic growth, the president said.
President Sirisena said that the people are of the view that the degradation of society was demonstrated by the conduct of MPs in parliament.
President Maithripala Sirisena says he opposes the proposal to form a national government again.