With major presidential contenders expected to ditch the public financing system entirely for the first time in 2008, legislation was introduced in both chambers Tuesday that would dramatically increase matching funds and spending limits for participating candidates, a plan the proposals’ authors claim may revive an ailing — and increasing irrelevant — system.

“As frontrunner candidates opt out, the current system acts as an incentive to their competitors to do the same or be crushed under superior fundraising without spending limits,” said Rep. Marty Meehan (D-Mass.), one of the bill’s sponsors. “The system in place right now is unsustainable.”

And while most Republicans and Democrats agree that the current public financing system is desperately in need of an update, they do not agree on the best way to tinker with the system. The divide, based in part on whether regulation fundamentally is a good thing, is muted in the House: The sponsors recently enlisted Democratic Caucus Chairman Rahm Emanuel (Ill.) and say other Democratic leaders are soon to follow.

“There is support among Democratic leadership for overhauling the current system,” Meehan said. “In the end, there will be support for an up-or-down vote.”

But in the Senate, where the whims of even one Member can signal certain death for controversial proposals — which adequately would describe nearly all campaign finance bills — the overhaul’s prospects are less than rosy.

“Obviously, [the public financing system] is about to go completely belly up,” said Senate Minority Whip Trent Lott (R-Miss.) on Tuesday. “There are some on our side that have indicated we should have never started public financing of campaigns.” Lott called the idea behind public financing “a dinosaur.”

The proposal — also sponsored by Reps. Christopher Shays (R-Conn.) and David Price (D-N.C.) and Sen. Russ Feingold (D-Wis.) — would not go into effect until the 2012 elections and would increase the matching funds for presidential primaries from the current 1-to-1 match up to $250 to a 4-to-1 match for up to $200 of an individual’s contribution.

The bill also would up current spending limits for participating candidates from roughly $45 million to $150 million in the primaries and provide a one-third spending limit increase for general elections, from $75 million to $100 million — amounts that would be indexed for inflation.

To qualify, candidates must agree from the get-go to accept public financing through Election Day and raise — in amounts of $200 or less — $25,000 in 20 different states.

So far, Democratic leadership in the Senate is waiting to review the bill before it decides to put its weight behind it.

One likely foe would be Senate Minority Leader Mitch McConnell (R-Ky.), a frequent critic of increased campaign finance regulation and, especially, any plans that would increase the use of public money in presidential elections.

McConnell’s office declined to comment for this article. One Republican aide, however, doubted McConnell’s hand ever would be forced on the issue, not necessarily just because of the Minority Leader’s presumed opposition, but because of the skepticism of a handful of key Senators about public financing.

But in the end, McConnell might not need to filibuster, according to the aide: “It might not get out of committee.”

Campaign finance reform groups were quick to praise the proposal. Fred Wertheimer, president of Democracy 21, said it is hypocritical for lawmakers to blast a system that both Republicans and Democrats benefit from.