The impasse that threatens to lead to a government shutdown is not simply about the federal budget. Some of the sticking points relate to policy and have been attached to the budget as “riders.” On Thursday, a few GOP policy proposals emerged as possible deal-breakers for Democrats, as leaders sought to reach an agreement that would keep Washington operating:

• Planned Parenthood. Republicans are seeking to defund Planned Parenthood, the nation’s largest abortion provider. The organization receives millions of federal dollars for non-abortion services for low-income people, including cancer screenings and contraceptives. Conservatives have questioned the integrity of the group and argued that federal funding frees up other money that Planned Parenthood can use for abortions, while liberals say that taking away funding would harm women’s health efforts.

• Abortion in the District. Although federal law bars the use of federal money to pay for abortions, that ban does not extend to state funding. Seventeen states and the District use their portion of Medicaid funding to help some low-income women obtain the procedure. Because District money is overseen by Congress, the city had to gain congressional approval before extending that benefit.

That permission came two years ago, after Democrats took control of the White House and both chambers of Congress. Now, the Republican-led House has proposed revoking that permission, sparking fear among some abortion-rights advocates that Democrats may use the issue as a bargaining chip to save Planned Parenthood’s funding.

• The environment. Republicans are aiming to curb the Environmental Protection Agency’s reach, especially its role as a regulator of the greenhouse gases that contribute to climate change. GOP lawmakers have proposed riders that would limit the agency’s ability to oversee coal mining and enforce the Clean Air Act.