People are growing pessimistic that the White House and congressional leaders can reach an agreement on avoiding the fiscal cliff, a new Gallup poll said Wednesday.

Fifty percent said a deal was very or somewhat likely, compared to 48 percent who felt otherwise. Over the previous three weeks, Gallup said, a "solid majority of Americans were generally confident leaders would reach a deal to avert the so-called fiscal cliff."

If nothing is done, Bush-era tax cuts will expire Monday, and automatic spending cuts will go into effect Jan. 2. President Barack Obama is due to leave Hawaii later Wednesday, and Congress returns Thursday.

The data reflects views from Dec. 21-22.

Gallup also found Americans showed "increased confidence in the various Democratic players involved in the negotiations, including President Barack Obama, Democratic leaders in Congress, and Senate Majority Leader Harry Reid."

Fifty-four percent approve of Obama's handling of the negotiations, up from 48 percent a week ago. That coincides with a small increase in Obama's approval rating.

"That increase may at least partly reflect Americans' response to Obama's actions in the aftermath of the tragic Newtown, Conn., school shootings Dec. 14, combined with his ongoing efforts in regard to the fiscal cliff," Gallup said.

There's been no major change in ratings of Republican leaders generally, or of Republican House Speaker John Boehner.

To read more: www.gallup.com