Mississippi Gov. Haley Barbour says health care legislation pending in Congress could make Medicaid too expensive for his state by putting lots more people on the program.

The Republican governor sent a letter to U.S. senators Friday to repeat what he has been saying for months — that a dramatic increase in Medicaid enrollment would strain Mississippi’s budget and could force state officials to increase the sales tax, the income tax or both.

Medicaid is a government health insurance program for the needy, aged, blind and disabled and for low-income families with children. It is paid by federal and state dollars.

About one-fifth of all Mississippi residents are already on Medicaid. Barbour says a federal proposal could increase that to one-third.