Sen. John McCain vowed Wednesday to prevent Democrats from bringing the defense authorization bill to the floor next week.

The Arizona Republican, who is ranking member of the Armed Services Committee, said Democrats were using the defense measure as a tool to push liberal agenda items in the runup to the midterm elections.

“So I intend to block it, unless they agree to remove these onerous provisions,” he said.

McCain blasted Senate Majority Leader Harry Reid (D-Nev.) for attaching both the DREAM Act and a proposal to end the use of secret holds in the Senate to the measure. McCain also criticized Democrats for using the defense bill to try to repeal the military’s “don’t ask, don’t tell” policy.

“It’s a pure political act for Harry Reid, who is worried about his own re-election and that of the Democrats in the Senate,” McCain said.

National Republican Senatorial Committee Chairman John Cornyn (Texas) added in a statement that the amendments were “transparently political” and a curious departure from the Democrats’ pledge to focus on jobs and the economy during this work stretch.

McCain was opposed to adding the DADT language, which would repeal the military’s policy barring openly gay people from serving in the military, when the Armed Services panel took up the defense authorization measure in May. Democrats had hoped McCain would soften his stance after decisively winning his party’s primary in Arizona last month, but given his remarks Wednesday, that does not appear to be the case. McCain said he had not spoken this week with Armed Services Chairman Carl Levin (D-Mich.), who suggested Tuesday the defense measure could be wrapped up in a matter of days if a time agreement is reached. With McCain’s filibuster threat, that does not appear a likely scenario.

Although some Democrats have suggested the caucus stay focused on jobs and the economy this work period, others suggest that repealing DADT could help rally liberals to the voting booths in November. Gay rights activists have been pushing hard over the last several weeks, and one Democratic leadership aide suggested McCain’s filibuster threat could backfire.

“Channeling the tea party crowd, comments like this by Sen. McCain continue to highlight the new and creative ways that Republicans are using … to just say, ‘hell no,'” Reid spokesman Jim Manley said.

Reid is expected to file a procedural motion on the defense bill this week and tee up a Tuesday test vote on the measure, although it remains unclear whether he has the 60 votes needed for cloture.