A Gallup poll released Thursday showed independents continue to favor the Republicans by a 10-point average margin for this fall's midterm elections.

By a 45-35 percent spread, independent registered voters said they would vote for the Republican congressional candidate in their district. Since March, the margin of independents' preference for Republicans over Democrats has fluctuated between 8 and 12 percent.

The poll is one sign the GOP could have momentum heading into the fall midterm elections. Several Republican leaders have predicted the GOP will take back the House and make significant gains in the Senate.

But Democrats have pointed to several Republican losses in recent special elections, saying Democratic candidates have run better campaigns and the GOP's message is falling on deaf ears.

The June Gallup survey, which is a monthly average of its daily tracking polls, shows that about 20 percent of independents are undecided or favor a third-party candidate, meaning both major parties have opportunities to pick up their support of a greater portion of the key voting bloc.