The House could push back a vote on a resolution authorizing military strikes on Syria by as long as a week, according to a memo Majority Leader Eric Cantor (R-Va.) sent to Republican lawmakers Friday.

“Understanding that there are differing opinions on both sides of the aisle, it is up to President Obama to make the case to Congress and to the American people that this is the right course of action,” Cantor wrote in a memo outlining the House GOP’s fall agenda. “Members should expect a robust debate and vote on an authorization of use of military force pertaining to Syria in the next two weeks.”

In a joint statement last Saturday, the top four members of the House Republican leadership said they expected the House to consider a Syria resolution “the week of September 9th.”

While Cantor and Speaker John Boehner (R-Ohio) support a resolution authorizing strikes, opposition is mounting among the Republican rank-and-file, and it is now likely that the House will wait until the Senate votes first. The Senate action could come next week, after the Foreign Relations Committee approved a revised force resolution on Wednesday.