The struggling candidate’s campaign manager, Addisu Demissie, warned that after weaker-than-expected fundraising in the early part of September, the campaign needs to rake in another $1.7 million before the last day of the financial quarter on Sept. 30.

“Without a fundraising surge to close out this quarter, we do not see a legitimate long-term path forward,” Demissie wrote in the Saturday memo to staff and supporters. “The next 10 days will determine whether Cory Booker can stay in this race.”

Booker was one of the first candidates to build a substantial operation in critical early states, and his ground game in Iowa has been praised by local activists, but the large headcount is expensive.