WASHINGTON -- A symbol of President Barack Obama's uphill fight to win congressional approval for a U.S. raid on Syria was highlighted Monday when U.S. Rep. Jim Himes, D-Conn., said he no longer supports such an attack and is now "leaning toward `no.' "

Obama is expected to use a Tuesday night speech to the nation to present reasons why the U.S. should launch a military attack against Syria in retaliation for what he says was the Syrian government's use of chemical weapons last month against insurgents in that country's civil war.

But the 4th District congressman said he's "skeptical'' that such an U.S. attack would be the best move because:

There is scant international support for such a step.

Hezbollah and other "very unsavory groups'' in Syria might get control of the chemical weapons in the chaos of a raid.

The unintended consequences of an attack also could include a retaliatory Hezbollah attack on Israel.

His constituents are strongly opposed to U.S. intervention. "When my constituents are very, very clear on an issue, I would vote the other way only if the case was very overwhelming,'' he said. "That's not the situation here.''

At a town hall meeting Sunday in Darien, Himes and U.S. Sen. Richard Blumenthal, D-Conn., heard citizens speak for and against a military strike, but a straw vote showed that most of the 425 people attending were against any U.S. raid.

Himes said he will watch Obama's speech Tuesday night to see if the administration has been able to pick up more international support and for assurances that a raid wouldn't trigger wider violence in the region.

Last month, fresh from visiting Jordan and Turkey as a member of the House Intelligence Committee, Himes had urged Obama to order a cruise missile attack on Syrian artillery as punishment for using chemical weapons in defiance of Obama's red-line warning against such a step.

At the time, Himes adamantly rejected the use of U.S. ground troops to punish Syrian President Bashar al-Assad, but said a cruise missile attack would make it "very plain that when you cross the red line set by the president of the United States, there's a price to be paid.''

Blumenthal said Monday that he has heard the views of Connecticut voters on all sides of the issue and "will consider them preeminently in my decision regarding the authorization of military force, which I expect to make in the next day or so.''

A spokesman for U.S. Rep. Elizabeth Esty, D-Conn., said she also was undecided about whether to approve of Obama's plan to order an attack on Syria. U.S. Rep. Rosa DeLauro, D-Conn., also is undecided, her communications director said.

U.S. Sen. Chris Murphy, D-Conn., who voted last week against U.S. intervention when the Senate Foreign Relations Committee approved a pro-attack resolution, said Monday that he doesn't plan to change his views on the issue.

He joined Obama in carefully hailing the proposal for Assad to put his chemical weapons under international control.

"If it were a truly international effort, this could be a very positive development,'' Murphy said. " If Assad were to lose control over all of his chemical weapons, I would hope that would obviate the push for U.S. air strikes.''

Informal tallies of Senate and House members showed that Obama was facing an embarrassing failure in his quest for congressional approval for a raid. Against that backdrop, the president late Monday eagerly welcomed Russia's dramatic proposal for Syria to surrender its chemical weapons to international control.

Using six network television interviews to set the stage for a nationally televised address Tuesday night, Obama said it was "possible" for Syria to avert the showdown if the offer to give up the weapons was "real."

It also would give him a chance to avert a showdown on Capitol Hill, where his prospects appeared dim.

"I think it's certainly a positive development when the Russians and the Syrians both make gestures toward dealing with these chemical weapons," Obama said in an interview with CNN.

"It is a potentially positive development. I have to say it's unlikely that we would have arrived at that point where there would be public statements like that without a credible military threat to deal with the chemical weapons use inside Syria," Obama added.

The Russians apparently seized upon seemingly off-hand comments by Secretary of State John Kerry during a stop in London that Bashar al-Assad could end the threat of U.S. military action if "he could turn over every single bit of his chemical weapons to the international community in the next week --turn it over, all of it without delay and allow the full and total accounting."

The Russian proposal outlined by Russian Foreign Minister Sergey Lavrov was immediately accepted by visiting Syrian Foreign Minister Walid al-Moallem. It was not immediately clear what impact the Russian proposal would have on a Senate vote to authorize the use of military force that could come as early as Wednesday, the 12th anniversary of the 9/11 attacks.

An Associated Press survey completed before Russia's proposal found 23 of the Senate's 100 members favoring military authorization and 10 more leaning that way. The survey found 20 senators opposed to military action, with 14 others leaning that way.

The AP reported that the remaining 33 senators were undecided or publicly uncommitted, raising the possibility of a 60-vote majority to approve an authorization to use military force.

In the House, 201 of the 433 sitting lawmakers had not yet taken a public position, the AP found. The news service found fewer than a dozen House members had declared support and 150 had voiced opposition or leaned that way.