The Republican effort to defund Planned Parenthood may very well lead to another government shutdown next month.

Planned Parenthood has been under fire since a conservative anti-abortion group released videos earlier this year, which allegedly show medical workers affiliated with the pro-choice nonprofit discussing the sale of aborted fetal tissue. Following the release of undercover sting videos, a group of GOP senators tried to pass a bill to strip the group of its federal funding in August. However, the bill failed to get enough votes.

Nonetheless, 31 conservative Republicans have pledged to vote against any spending bill that includes money for Planned Parenthood, despite the fact that federal law restricts money from going toward abortions, reports New York Magazine. If they're successful in blocking a spending bill from passing by the Sept. 30 deadline, then the government will shut down on Oct. 1.

Leading the crusade to shut down the government and defund Planned Parenthood is 2016 presidential hopeful Texas Sen. Ted Cruz, reports CNN. The Republican senator has reportedly conducted a strategy session at his office with several other far-right conservatives on how to stand up to the GOP leadership, who want to avert a shutdown.

The House is also scheduled to vote next week on legislation to defund Planned Parenthood for one year while Congress investigates the organization's use of fetal tissue donations.

Following the congressional recess, House Speaker John Boehner launched an effort to avert a government shutdown on Wednesday. The Republican leader warned his party that allowing a government shutdown would not cut government funding to Planned Parenthood or end the sale of aborted fetal tissue. Boehner also noted that a number of House Republicans have agreed to pass a stopgap measure that would keep the government funded through December.

Meanwhile, Senate Majority Leader Mitch McConnell has said that the Senate will not pass the measure, since Republicans do not have enough votes to overcome a Democratic filibuster or a presidential veto.