Jan. 27 (Bloomberg) — Republican U.S. senators opposed to Obamacare said the best alternative would be a narrower system of tax credits for Americans to buy health insurance without any of the mandates for people or companies to participate.

The proposal today by Senators Orrin Hatch of Utah, Richard Burr of North Carolina and Tom Coburn of Oklahoma is a response to criticism from President Barack Obama that Republicans have offered no credible alternatives to his $1.4 trillion expansion of the U.S. health-care system. The senators' plan came with no estimate of its costs or a timetable for formal legislation.

Aides to the senators said they don't expect any Obamacare replacement plan to be seriously considered by Congress before the next U.S. presidential election, which is more than two years away. In the meantime, they need to build a base for what that alternative may be, said Robert Blendon, a professor of health policy at the Harvard School of Public Health in Boston.