WASHINGTON — Senate Minority Leader Harry Reid confirmed Thursday that Democrats this month will oppose any stopgap spending bill that would punt current government funding and policies into 2017, a strategy favored by conservative Republicans who don’t want a lame-duck session.

“Everyone should be alerted today to this: We are not going to agree to a long-term CR,” Reid told reporters on a conference call, referring to a continuing resolution. “We are not doing anything into next year. The Republicans should be made aware of that right now.”

Lawmakers have until Sept. 30 to pass a continuing resolution to avoid a government shutdown when fiscal 2016 funding expires. Reid’s comments on the length of a stopgap, his most forceful to date, came after the Nevada Democrat apparently discussed the matter with President Obama.

Reid added that Democrats would likely accept a measure that continues funding into December, “up to Christmas,” but nothing longer.

The last two years, Congress has passed continuing resolutions in September that extend funding into early or mid-December, leading to omnibus packages that provided fresh spending guidance for government agencies and programs. Like most Democrats, many Republican appropriators and defense hawks favor following the same playbook this year.

But a number of conservatives, led by members of the hardline House Freedom Caucus, want a six-month CR in September that would run into March 2017.

Reid warned that if Republican leaders play their cards wrong, “we’re headed straight for another unnecessary government shutdown.” His opposition to a long-term continuing resolution is shared by House Minority Leader Nancy Pelosi, D-Calif.

Senate Majority Leader Mitch McConnell, R-Ky., has not stated a preferred duration for a CR. But two of his top lieutenants, John Cornyn of Texas and John Thune of South Dakota, the No. 2 and No. 3 Senate Republicans, have said they’d rather push the matter to 2017.

“I’m sure our members will discuss the length of the CR again next week when they’re back,” said Don Stewart, a spokesman for McConnell. “But remember, the only reason a CR is even being discussed is because Democrats – despite Reid’s call for an end to the filibuster – are filibustering all the approps bills.”