Democratic congressional staffers and party operatives are streaming into western New York as the special election for former Rep. Chris Lee’s (R) seat moves into its climactic final days.

House Minority Whip Steny Hoyer (Md.) is planning to send staff to help Democrat Kathy Hochul get out the vote, but there was no plan as of press time for him to travel to the district, according to an aide. Hoyer staffers will join ground troops already deployed by the Democratic Congressional Campaign Committee who are being led by Brynne Craig, the DCCC’s field director.

The costs of the special election are piling up. As of Tuesday, more than $1.3 million had been spent in the district by outside groups, according to the nonpartisan Center for Responsive Politics (CRP).

And both political parties have poured money into the race.

In the last two weeks, Hochul has received $30,000 from the leadership PACs and campaign committees of Democratic lawmakers, including $5,000 in contributions from the leadership PACs of House Minority Leader Nancy Pelosi (Calif.), Hoyer and Senate Policy Committee Chairman Charles SchumerCharles SchumerOvernight Finance: Dems introduce minimum wage bill | Sanders clashes with Trump budget chief | Border tax proposal at death's door Sanders, Democrats introduce minimum wage bill Top House, Senate Dems ask Interior not to eliminate national monuments MORE (D-N.Y.), according to CRP data.

That’s in addition to the almost $300,000 the DCCC has invested in advertising and its field operation.

Schumer has campaigned for Hochul, and Sen. Kirsten GillibrandKirsten GillibrandBill would require sexual assault, social media training for military recruits Dem senator: 'One of our closest allies' expressed concern about intelligence sharing Intel chief quiet on whether Trump asked him to deny Russia evidence MORE (D-N.Y.) will be in Buffalo on Saturday to rally her supporters. Other big-name Democrats are expected to appear in the closing stages of the race.

Meanwhile, Republican Jane Corwin has been helped by a series of appearances by GOP House leaders and $40,000 in donations from Republican lawmakers. The National Republican Congressional Committee (NRCC) has invested more than $400,000 in advertising and is hosting nightly phone banks through Monday. NRCC Chairman Pete Sessions (Texas) even made phone calls for Corwin last Thursday night.

She also got some help from Florida Rep. Allen West (R), who taped a robocall for her. On Wednesday, Corwin landed the endorsement of the U.S. Chamber of Commerce.

Conservative groups such as American Crossroads and the California-based Tea Party Express are helping marshal Corwin supporters. 

The Tea Party Express also denounced Independent candidate Jack Davis, who is running on the Tea Party line, as a “fraud” in a bid to drive conservative voters back into Corwin’s camp.

Davis, a mostly self-funding candidate, has remained third in polling on the race but shows no signs of dropping out.

—Mike Lillis contributed reporting.

--Updated May 20 at 10:26 a.m.