WASHINGTON — Sen. Mark Kirk, R-Ill., who spent Tuesday fundraising in New York, will report contributions of more than $1 million in the first quarter of this year, according to a Kirk aide.

Kirk closed out the first quarter of fundraising with two events in New York the day after Rep. Tammy Duckworth, D-Ill., announced her Senate bid.

If Kirk and Duckworth are the nominees, the 2016 battle for the Illinois Senate seat will cost tens of millions of dollars – not counting third-party political players who are likely to pour money into the contest.

Both Kirk and Duckworth are prodigious fundraisers.

Kirk, who has not had to run since 2010, had $2,006,145 cash-on-hand as of Dec. 31, according to Federal Election Commission reports for the Kirk for Senate committee.

Duckworth, who had to fund campaigns in 2012 and 2014, had $1,052,287 cash-on-hand as of Dec. 31, according to FEC reports for the Duckworth for Congress committee.

Kirk stepped up his fundraising for the 2016 campaign earlier this month.

Gov. Bruce Rauner headlined an event for him in Chicago and Senate Majority Leader Mitch McConnell, R-Ky., and other GOP Senate leaders were the draw at a reception for Kirk here.