Republican Reps. Michele Bachmann (Minn.) and Ron Paul (Texas) missed another key vote on Tuesday, when the House voted 229-123 to reject a Senate-passed deal to extend a payroll tax cut.

Bachmann and Paul, the only two sitting members of Congress running for president in 2012, were also absent on Friday when the House passed a $1 trillion omnibus spending bill to fund the federal government.

The two lawmakers have missed most of their votes in the second half of 2011 as they crisscross the country in pursuit of the GOP nomination. With Iowa's first-in-the-nation caucuses only two weeks away, both would be at a disadvantage compared to their primary competitors if they left the campaign trail to return to Washington.

Paul is in New Hampshire on Tuesday, while Bachmann is midway through a bus tour of Iowa's 99 counties.

Both Bachmann's and Paul's last roll-call votes came on Dec. 7, when Bachmann was in Washington to address the Republican Jewish Coalition forum. Paul, who also voted the day before, was the only major GOP candidate not invited to the forum.

- This post was updated at 2:23 p.m.