Rep. Dan Donovan and primary challenger Michael Grimm tried to build up some last-minute support Sunday before Tuesday's vote. 

The two Republicans attended an annual Polish festival in Snug Harbor on Staten Island.

Donovan is seeking re-election and is hoping to secure his party's nomination in the primary.

Grimm is trying to win back the seat, which he held until resigning in 2014 after pleading guilty to tax fraud.

The polls open Tuesday morning at 6 a.m. and close at 9 p.m.

The winner will go on to face the Democratic nominee in the general election in November.