Wall Street firms reacted angrily to the tax proposals, with several saying they would explore ways to end their participation in the bailout program.

The chief executive of Citigroup, Vikram S. Pandit, sent employees a memorandum Friday saying, “The work we have all done to try to stabilize the financial system and to get this economy moving again would be significantly set back if we lose our talented people because Congress imposes a special tax on financial services employees. It would affect countless number of people who will find it difficult, if not impossible, to pay back the bonuses that they earned.”…

Mr. Obama, who initially said he welcomed the effort by Congress to tax bonuses, is now taking a more measured approach. The White House press secretary, Robert Gibbs, said the administration would have to consider the impact of the legislation on its wider efforts to prop up banks and increase the flow of consumer credit to families and small businesses.