House Speaker Paul D. Ryan (R-Wis.) and President Trump leave a luncheon celebrating St. Patrick’s Day on March 16. (Win McNamee/Getty Images)

An organization aligned with House Speaker Paul D. Ryan (R-Wis.) is launching a radio advertising campaign Tuesday designed to apply a closing round of pressure on House conservatives to vote for his overhaul of the Affordable Care Act by underscoring President Trump’s support for the measure.

The American Action Network said it is making a six-figure investment in radio commercials running mostly in districts represented by members of the House Freedom Caucus, a group of about three dozen hard-right conservatives who have been reluctant to support Ryan’s bill.

The narrator of the ads portrays the Ryan proposal as a “conservative plan to end Obamacare” and notes Trump has voiced support for it. Trump is expected to press Republicans to pass the bill in a Tuesday meeting with GOP lawmakers. He performed well in the election in the conservative terrain represented by Freedom Caucus members, which places them under heavy political pressure not to resist his wishes.

“The time to act is now,” says the narrator.

The ads will run in the districts of members including Rep. Mark Meadows (R-N.C.), the head of the Freedom Caucus. His group has pushed for a more sweeping dismantling of the ACA but has not officially taken a position against the House GOP bill.

“They’re already whipping with a whip that’s about 10 feet long and 5 feet wide,” Meadows said Monday of House GOP leaders. “I’m trying to let my members vote the way that their constituents would want them to vote.”

Other members targeted by the ad include Reps. Dave Brat (R-Va.), Jim Jordan (R-Ohio) and Gary Palmer (R-Ala.), who are also in the Freedom Caucus.

House Republican leaders on Monday night unveiled tweaks to their legislation. They are hoping the changes, which include providing states more latitude in operating Medicaid, will help them secure the votes needed to pass the measure in the lower chamber on Thursday.

The AAN has been using television and radio to pressure both moderate and conservative House Republicans to support the bill.