A plurality of voters now opposes further U.S. military action in Libya, and most say President Obama needs congressional approval to continue those operations.

A new Rasmussen Reports national telephone survey finds that just 26% of Likely U.S. Voters feel the United States should continue its military actions in Libya. Forty-two percent (42%) are opposed and 32% are undecided. (To see survey question wording, click here.)

But 59% agree the president should get the approval of Congress if he wants to continue U.S. military action in Libya. Twenty-one percent (21%) say congressional approval is not needed. Another 20% are not sure.

This marks a jump in support for congressional authorization from mid-March just after the president committed U.S. military forces to helping anti-government rebels in Libya. At that time, 47% said the president should have gotten congressional approval before ordering the military into action in Libya. Thirty-four percent (34%) said the prior approval of Congress was not necessary, but 19% were undecided.

Most voters remain skeptical of how soon U.S. military involvement in Libya will end. Just 32% think it is at least somewhat likely that U.S. military operations in Libya will be over by the end of the year, with 10% who say it is Very Likely. Fifty-four percent (54%), however, think it is unlikely those operations will be done by the close of the year, including 14% who say it is Not At All Likely. Another 14% are not sure.

This is comparable to findings in late April.

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The survey of 1,000 Likely Voters was conducted on June 10-11, 2011 by Rasmussen Reports. The margin of sampling error is +/- 3 percentage points with a 95% level of confidence. Field work for all Rasmussen Reports surveys is conducted by Pulse Opinion Research, LLC. See methodology.