Cabinet ministers on Friday played down remarks made the previous day by a close aide to Prime Minister Shinzo Abe hinting at a delay of the consumption tax hike long planned for October.

The government has maintained that the consumption tax will be raised from 8 percent to 10 percent unless the economy suffers a shock on the scale of the global financial crisis triggered by the 2008 collapse of U.S. investment bank Lehman Brothers Holdings Inc.

"It is necessary to raise the tax ... to secure a stable source of revenue for a social security system oriented to all generations in dealing with the biggest challenge of a declining birthrate and aging population," Finance Minister Taro Aso said at a news conference.