The House has left town for its August recess and the Senate is departing, which leaves a hefty list of unfinished business. Lawmakers have just 10 legislative days in September to ensure that the government stays open.

Here is Congress' must-do list:

--The 12 annual spending bills that fund the government remain in limbo over disparate disputes, from the Confederate flag to defense budgets. Congress is likely to approve a so-called continuing resolution to keep the government operating temporarily, which leaders hope they can do by Pope Francis' address to lawmakers Sept. 24. Conservatives insist they won't back legislation financing Planned Parenthood, under fire after its officials were secretly recorded discussing how they obtain fetal tissue for research.

--Congress must vote by Sept. 17 on the international nuclear deal with Iran. Both House and Senate Republicans have set the stage for votes on a resolution of disapproval, which President Barack Obama has promised to veto. Congress would then have to vote within 10 days on whether to override the veto.

--The government's ability to pay its bills expires around Oct. 30, so Congress will have to extend the government's borrowing authority by then or face a first-ever federal default. That likely means there will be demands and drama attached to that showdown.

--Congress has until Oct. 29 to renew federal highway programs. Lawmakers approved a three-month extension last week, but a deadlock over finances thwarted an effort to pass a multiyear version that would give state and local governments confidence to map long-term road-building plans.

--Already expired is the ability of the Export-Import Bank to make fresh loans. The tiny federal agency makes low-cost borrowing available to help American exporters sell their products, which conservatives complain is corporate welfare.

--Lawmakers must resolve disputes over spending levels in their annual defense policy legislation. The White House has threatened to veto the legislation.

--Deadlines are also approaching for lawmakers to renew the Federal Aviation Administration's authority to spend money, child nutrition programs and pipeline safety standards, all of which expire Sept. 30.

--High on the may-do list: A fresh GOP attempt to repeal Obama's health care law and perhaps replace it with an alternative -- if Republicans can agree on something. Also, an effort to improve cybersecurity legislation.