WASHINGTON — To prevent a possible run on banks in the depths of the financial crisis four years ago, Congress expanded government insurance for certain bank deposits to include totals above the usual $250,000 limit. Now that the ceiling is about to be reimposed, community banks fear they will lose customers to bigger banks and want Congress to come to their rescue.

They are opposed by conservative groups, among others, who say the Transaction Account Guarantee program is no longer needed and discourages the wealthy from investing in the economy.