A fundraising appeal from the Democratic Congressional Campaign Committee warns supporters that "Tea Party Republicans are threatening to shut down the government on Friday unless we surrender to their outrageous demands."

The fundraising email, penned by DCCC Chairman Steve Israel (N.Y.), went out late Wednesday and asks for small donations to the committee's "GOP Accountability Fund," setting a goal of raising $50,000 by Friday "so we can hold Speaker John BoehnerJohn Andrew BoehnerSpeculation mounts, but Ryan’s job seen as safe Boehner warns Trump: Don't pull out of Korea-US trade deal GOP Rep: Ryan wasting taxpayers dollars by blocking war authorization debate MORE and his Tea Party fringe Republicans immediately accountable for shutting down the government."

"The world is watching our next move," Israel wrote. "Will we cave to the Tea Party's disgraceful act of political extortion or will we fight back with the full force of our grassroots strength?" 

The email says the GOP's posture in the shutdown standoff amounts to "blackmail." 

The National Republican Congressional Committee responded to the fundraising appeal Wednesday, accusing Democrats of "exploiting" the nation's financial crisis.

"House Democrats are exploiting our financial crisis and using it for political gain while Republicans are addressing it as an American challenge that calls for placing our nation and our economy ahead of partisanship," NRCC spokeswoman Joanna Burgos said in a statement.

House Republicans announced Wednesday that they plan to vote Thursday on a stopgap spending bill to keep the government running for another week. The measure would cut another $12 billion from the budget.

House Speaker John BoehnerJohn Andrew BoehnerSpeculation mounts, but Ryan’s job seen as safe Boehner warns Trump: Don't pull out of Korea-US trade deal GOP Rep: Ryan wasting taxpayers dollars by blocking war authorization debate MORE (R-Ohio) and Senate Majority Leader Harry ReidHarry ReidThe Memo: Trump pulls off a stone-cold stunner The Memo: Ending DACA a risky move for Trump Manchin pressed from both sides in reelection fight MORE (D-Nev.) will meet with President Obama at the White House Wednesday night to continue working toward a long-term budget agreement.

-Updated at 7:42 p.m.