President Joe Biden will hold a fund-raiser for John Fetterman in Philadelphia next week

President Joe Biden will hold a fund-raiser with Democratic Senate candidate John Fetterman in Philadelphia next week to boost his campaign in a tight and closely watched Senate race that could determine control of the chamber.

The Oct. 20 fund-raiser in Philadelphia comes days after Senate fund-raising reports are due in a race that has tightened with just four weeks to go.

Biden hasn’t done much public campaigning for midterm candidates but has hosted several fund-raisers to bring in money for Democrats who he hopes can mount a challenge from Republicans for control of Congress. Last week he attended a fund-raiser at the home of New Jersey Gov. Phil Murphy, vice chair of the Democratic Governors Association, as well as an event in New York for the Democratic Senatorial Campaign Committee.

While his approval ratings have lagged amid a rocky economy and inflation, Biden remains a prolific fund-raiser and has ramped up efforts to assist in big-dollar contests.

Pennsylvania’s Senate race has already set records for cash spent. Republican candidate Mehmet Oz reported raising $17 million in the last quarter, including a $7 million loan. Fetterman reported bringing in $22 million, though neither campaign has reported how much cash it has left on hand headed into a crucial final stretch when buying up TV time and get-out-the-vote efforts will be critical. Outside groups have also invested heavily, especially in recent weeks.

» READ MORE: Fetterman says Oz ‘lies about my record on crime,’ at stop in Southwest Philadelphia

The joint appearance for Fetterman and Biden comes a week after Biden announced a pardon of all federal “simple possession” marijuana convictions, something the lieutenant governor had long pressed for. It will also fall five days before the Senate contest’s only debate on Oct. 25.

Oz’s campaign responded to news of the fund-raiser by calling Biden the “inflator in chief.”

“John Fetterman’s desperate campaign is in a downward spiral and he is doing anything he can to try and undo the momentum Dr. Oz has gained over the past several weeks... Tying himself to a failed president who has done more than any leader in history to cause skyrocketing inflation and higher gas prices for Pennsylvania families is also not a winning strategy,” campaign spokesperson Brittany Yanick said.

Former President Donald Trump rallied with Oz and gubernatorial nominee Doug Mastriano in Wilkes-Barre in early September. Trump and Biden, who campaigned heavily in Pennsylvania during the 2020 presidential contest, are expected to remain active in Pennsylvania’s Senate race.