(CNN) - The National Democratic Campaign Committee is trumpeting its latest fundraising totals, announcing Wednesday that it raised $15.9 million last month, making September one of its strongest fundraising months in history, the group said.
The DCCC said it plans to spend $60 million on campaigning and voter outreach in the final days of midterm elections.
The announcement comes shortly after the National Republican Congressional Committee said it raised $11.2 million last month.
Despite the DCCC's significant fundraising advantage, the Republican candidates have also benefitted from outside conservative groups that have raised millions of dollars for the GOP this election season. Though legal under campaign finance laws, Democrats have criticized these groups for pouring money into Republican campaigns without disclosing their donor lists.
The DCCC said in a statement that it has seen an increase in "small dollar contributions and individual donations in response to the unprecedented spending by shady Republican outside groups."
The Republicans need to win back 39 seats to regain the majority in the house.
–CNN Deputy Political Director Paul Steinhauser contributed to this report.