WASHINGTON (Reuters) – A mandate to purchase health insurance is likely to be part of a sweeping overhaul of the U.S. healthcare system that Congress hopes to enact by the end of the year, a top Democrat in the U.S. House of Representatives said on Thursday.

But House Majority Leader Steny Hoyer declined to say how such a mandate would work, whether it would be for individuals to purchase insurance or employers to provide coverage or a combination of both.

"I think you are going to find mandates will be part of the plan," Hoyer told reporters.

A number of House committees are involved in writing the legislation to revamp the $2.5 trillion U.S. healthcare system to contain rapidly rising costs and cover an estimated 46 million uninsured Americans. Hoyer is helping coordinate that effort.

The insurance industry is seeking a mandate for Americans to buy coverage, arguing that it help insurers make premium prices more affordable for the sick and also allow them to end the practice of excluding coverage for pre-existing conditions and charging higher premiums to sick people.

A number of lawmakers from both parties do not like the idea of imposing an insurance mandate on people who may be unable to afford it.

During his campaign for the Democratic presidential nomination last year, President Barack Obama argued against an insurance mandate, while his rival for the nomination, Hillary Clinton, who is now his secretary of state, backed it.

Hoyer said congressional Democrats believe a government plan should be part of a mix of insurance options available to people. The idea is opposed by Republicans and the insurance industry, which fears it will be unable to compete with a public plan.

Hoyer declined to say what the public plan would look like, but said Democratic leaders would reach out to Republicans to try to address their concerns.

"We believe that a public option clearly is going to be necessary," Hoyer said.

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