House Democrats will meet Sunday afternoon for a “classified, member-only” briefing on Syria that suggests President Obama is wasting no time rallying support in his party for a military strike on Syria, which he decided should receive congressional approval.

“In the coming days, my administration stands ready to provide every member with the information they need to understand what happened in Syria and why it has such profound implications for America’s national security,” Obama told reporters at the White House Saturday afternoon.  “And all of us should be accountable as we move forward, and that can only be accomplished with a vote. ”

British Prime Minister David Cameron suffered a humiliating defeat Wednesday when Parliament voted against authorizing the use of military force in Syria.

The “urgent” email announcing the Democratic caucus meeting, obtained by the Washington Examiner, doesn’t say who will make the case for intervening.

Obama has an advocate in House Minority Leader Nancy Pelosi, D-Calif., though. “Assad gassing his own people is an issue of our national security, regional stability and global security,” she said in a Thursday statement.

Pelosi demonstrated her ability to deliver Democratic votes for hawkish positions in July, when she helped kill an amendment that would have narrowed the scope of the National Security Agency surveillance programs that members of her party often criticized when George W. Bush occupied the White House.