Both Clinton, D-N.Y., and McCain, R-Ariz., have made the summer suspension a major part of their campaign. Sen. Barack Obama, D-Ill., is against the move.

Speaker Nancy Pelosi, D-Calif., said and she has left the proposal off energy measures she may try to add to the supplemental Iraq war-spending bill. She said there was no guarantee that any moratorium on the gas tax would be passed on to the consumer.

Earlier, House Majority Leader Steny Hoyer, D-Md., said suspending the gas tax wouldn't be a "particularly positive policy."