WASHINGTON — House Speaker Nancy Pelosi is keeping the left flank of her caucus in the dark as she works on legislation to bring down prescription drug prices, congressional progressive leaders said, escalating a fight between progressives and moderates in the chamber.

“It’s like we’re back in the days of oral stories and there’s no written word. We’ve never seen anything in writing,” Congressional Progressive Caucus cochair Mark Pocan of Wisconsin said in an interview with BuzzFeed News.

His cochair, Rep. Pramila Jayapal of Washington, expressed similar concerns. “We have not seen any paper on anything,” she said. “We often found out what was being proposed through [the press] ... There is no detail, and the devil is in the detail.”

It’s so opaque, Pocan said he doesn’t think a single House member is involved “at the level they should be, even the committee chairs.” But it’s a particular problem for the CPC, whose members have identified lowering prescription drug prices as a top priority for the caucus and hope to pull the legislation leftward.

“What I think I see is the progressive caucus seems to be the one aggressively pushing to make this bill better,” he added. “We’re just really concerned that when something gets introduced ... and our members don’t support it, that we don’t have a bill that passes.” The CPC has more than 90 members in the House and, as a group, could easily sink any legislation.

The battle over the prescription drug bill exemplifies the internal fights House Democrats have had repeatedly on issues like Medicare for All and impeachment since reclaiming the majority in the chamber, as progressives push for bold action and sweeping policy proposals, while Pelosi and her leadership hold the moderate line. But while those battles have remained largely civil, at least in public, the prescription drug fight is different. Progressives are now openly criticizing Pelosi and her top advisers on both strategy and legislative specifics — or, they argue, the lack thereof.

Democrats agree they need to do something to curb skyrocketing drug prices, which have captured the spotlight in recent months, as the cost of lifesaving drugs like insulin have increased by hundreds of dollars per vial. Between 2001 and 2005, drugmaker Eli Lilly increased the price of its insulin drug, Humalog, from $35 to $234 per vial, a 585% increase, the Senate Finance Committee found. Between 2013 and 2019, two other manufacturers, Novo Nordisk and Sanofi, increased their insulin prices by 87% and 77%, respectively.

And it’s not just specialty drugs. A 2017 survey found that and that 25% of people reported an increase in the costs of their prescriptions from 12 months earlier. One in seven people don’t pick up their prescriptions at all because they can’t afford them.

But six months after reclaiming the House, there has been little movement from Democrats on lowering prescription drug prices.

“It seems like there’s very clear collaboration with the drug companies, which is not a bad thing, but it can’t just be them,” Jayapal said of leadership’s strategy on the prescription drug bill. “It’s also got to be with advocates, with members, so we’re sure that we’re addressing a lot of the most important pieces that we will need to see in a piece of legislation before we would vote for it.”

In a statement to BuzzFeed News, Henry Connelly, a Pelosi spokesperson, said it was “absolutely not true” that leadership was working with drug companies.

“Leadership and the committees of jurisdiction continue to solicit feedback and incorporate ideas from across the Caucus in order to develop the strongest, boldest possible legislation to lower prescription drug prices for all Americans,” Connelly wrote, adding that that top committee Democrats have been doing a listening tour with progressive members as they work on the bill.

Jayapal’s office later clarified in a statement to BuzzFeed News, “What the congresswoman intended to say was that many industry representatives have had a strong voice in these conversations — and she wants to ensure that we strive to center the voices those most impacted: consumers and advocates.”