WASHINGTON — President Donald Trump and his GOP allies on Capitol Hill have made it through nearly half their first year in power without a single major legislative achievement. If that’s going to change, it will have to start soon, a reality that Republican lawmakers will confront when they return to the Capitol on Monday from a weeklong break.

“We just need to work harder,” said the second-ranking Republican senator, John Cornyn of Texas, in an interview with KFYO radio in Lubbock, Texas, over the recess.

For now, the party’s marquee agenda items remain undone, their fate uncertain. The long-promised effort to overturn former President Barack Obama’s health law hangs in limbo in the Senate after barely passing the House. A tax overhaul that’s a top Trump priority is unwritten and in dispute, despite his recent claim on Twitter that it’s ahead of schedule.

“The president keeps saying the tax bill is moving through Congress. It doesn’t exist,” House Minority Leader Nancy Pelosi, D-Calif., said mockingly on Friday. “It doesn’t exist. There is no tax bill moving through Congress.”

Lawmakers will deal with those issues and more as Congress comes back into session, and realistically the window for action is closing fast. Seven legislative weeks are left before Congress scatters for a five-week August recess, a period when lawmakers are likely to lose momentum if they have failed to act on health care or taxes, and face GOP voters frustrated that they haven’t delivered.

Both issues are enormously difficult challenges, and the tax legislation must follow, for procedural reasons, passage of a budget, no small task on its own.

On top of it all, lawmakers are way behind on the annual spending legislation needed to keep the lights on in government. They were recently informed by Treasury Secretary Steven Mnuchin that they will have to raise the federal government’s borrowing limit before August, a daunting task ripe for brinkmanship.

Looming over everything is the investigation into allegations of Russian meddling in the 2016 campaign and connections with the Trump campaign. That investigation is in the hands of a special prosecutor and Congress’ intelligence committees. Former FBI Director James Comey, who was fired by Trump, is scheduled to testify before the Senate committee on Thursday.

“The Russia investigation takes a lot of oxygen, it takes a lot of attention,” said Republican Rep. Tom Cole of Oklahoma, a veteran lawmaker.