A Robert Mercer-backed political action committee spent close to $1 million in one week supporting Westchester County Executive Rob Astorino’s re-election bid.

Win For NY, a newly-registered PAC, reported spending $424,740 on Friday for media placement. That comes in addition to $127,479 spent on digital media and production and $424,740 for media placement and production.

That's $979,920 in total spent by Win For NY, including $15,460 for a countywide survey reported Monday.

PAC: Win For NY backs Rob Astorino bid

LATIMER: State senator says he drove unregistered car

DEBATE: Astorino, Latimer come ready to fight

LIST:Who's running in the Nov. 7 election

Billionaire Mercer, a supporter of the candidacy of Donald Trump for president last year, made two donations totaling $1 million to the PAC on Oct. 23.

With the Nov. 7 election fast approaching, both sides have ramped up the attacks – and campaign spending. Astorino, a Republican seeking his third term, is facing off against Democrat George Latimer, a Rye state Senator.

Astorino has criticized his opponent for $46,000 in unpaid taxes on a house in Rye owned by his wife. Latimer, a Democratic state Senator, went after Astorino over testimony in a New York City corruption trial where a Manhattan businessman said he helped Astorino get a Rolex watch.

In the most recent campaign disclosures filed with the state Board of Elections, Astorino’s campaign reported spending $975,794 in a period covering most of October. Latimer reported spending $585,350 during the same period.

Twitter: @marklungariello