WASHINGTON -- Breaking with party orthodoxy, 40 House Republicans urged Congress' supercommittee on Wednesday to consider all options for raising revenue as they hunt for ways to trim the $14.8 trillion national debt.

Though in a letter to the special debt-reduction panel the GOP lawmakers studiously avoided specific proposals that the signees admitted could shatter the group's unanimity, it seemed to at least crack the door open to the potential consideration of tax increases.

That seemed to separate the 40 Republicans from many in the GOP, who have said they would consider only new revenue generated by a stronger economy.

The GOP lawmakers joined 60 House Democrats in the letter, which also called on the panel to keep the door open for savings culled from benefit programs like Medicare, a path opposed by many Democrats.

In addition, the letter said the special committee should aim for $4 trillion in 10-year savings, more than triple the panel's mandated minimum target of $1.2 trillion.

At a news conference and in interviews Wednesday, Republican participants shied away from expressing an unconditional willingness to accept tax increases as part of a final deal.

Even so, the letter's bipartisan, conciliatory tone contrasted with the political atmosphere in Washington that has buffeted the supercommittee, which has made little evident headway just three weeks from the deadline for completing its work.

The signers make up about 1 in 6 House Republicans and nearly a third of its Democrats.