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The White House is getting advice from some former campaign advisers on how to win congressional support for a strike on Syria, Fox News has learned, with top White House aides soliciting their input during a long strategy session Tuesday afternoon.

The aides met with former top Obama campaign hands like strategist Anita Dunn, former deputy campaign manager Stephanie Cutter and long-time adviser David Axelrod.

While the president himself did not attend the meeting, attendees said the goal was to kick around ideas about how to help Obama win crucial votes in Congress as he faces a critical test of his presidency as soon as next week.

While Obama said at a separate meeting Tuesday morning with congressional leaders that he’s confident he will win the votes to pass a resolution in the House and Senate authorizing force, advisers to the president acknowledge privately they currently have no idea whether they will prevail or not because the situation is so fluid.

Attendees of the Tuesday afternoon strategy session said another goal of the meeting was to sharpen the administration’s message about the potential U.S. military action after a series of difficult news cycles for the White House.

Other attendees included two people who have been critical in helping plot media strategy for the president over the years -- former White House Press Secretary Robert Gibbs and former senior White House adviser David Plouffe, who also ran the president’s first White House campaign in 2008.

Senior administration officials stressed that the White House has regular meetings with the advisers on a variety of issues, but acknowledged that Syria is a particularly thorny one. Among the White House aides who attended Tuesday’s meeting were Chief of Staff Denis McDonough, Senior Adviser Dan Pfeiffer and Communications Director Jen Palmieri.

Sources familiar with the meeting said one idea that was kicked around was whether Obama should deliver a more formal address to the nation about Syria. In fact, other attendees of the meeting included the former chief White House speechwriter Jon Favreau and former White House national security spokesman Tommy Vietor.

There was no resolution on when the president might address the nation, in part because he will be overseas for the next few days in Sweden and then Russia for the G-20 Summit. One attendee of the meeting said decisions about a possible address to the nation are more likely to be made after the president returns to the country, and as Congress gets closer to actually voting on the Syria resolution, as the administration assesses when a possible address would have maximum impact.

Republican House Speaker John Boehner, who gave the president a boost Tuesday by going on the record for the first time to say he will support the mission and urging his colleagues to do the same, has been saying publicly for days that the White House should be waging a more aggressive campaign reaching out to the American people about the stakes in Syria.

A Boehner aide said again on Tuesday after the speaker’s endorsement that the onus is still on the White House to get the votes to pass the resolution authorizing the use of military force.

“Now, it is the president’s responsibility to make his case to the American people and their elected representatives,” said the Boehner aide.