Washington — Advocates of legislation to combat painkiller and heroin abuse are balking at changes House Republicans have made to a Senate-passed bill, arguing the revisions would compromise drug addiction prevention and recovery programs.

The House Judiciary Committee on Wednesday began considering legislation to address the opioid crisis, a major priority for members in both chambers this election year. But there have been simmering tensions between House Republicans and the senators who led the effort to get an opioid bill through the upper chamber over how quickly the House is moving and the specifics being proposed.

“Some of the most important ideas are missing from the House Judiciary Committee’s alternative,” Sen. Rob Portman, R-Ohio, who co-authored the Senate’s opioid bill, said on Tuesday. The Senate passed the legislation last month 94-1, and Portman called it “comprehensive. No other bill comes close.”

Portman faces a tough reelection race this year, and he is heavily promoting the opioid bill as part of his campaign. House leaders have dismissed the concerns, arguing that many of the worries expressed by Portman and advocacy groups are addressed either by expanded grant programs elsewhere in the legislation or under bills being examined by several committees.

“You’ll see streamlining a number of grants,” House Majority Leader Kevin McCarthy, R-Calif., said on Tuesday, adding that the overall House bill would be “a real improvement” over the Senate’s legislation.

At issue are how grants for treatment, prevention and recovery programs should be distributed. The House bill seeks to reduce the number of grant programs while giving states and localities more freedom in how they use the federal funds. But advocates of the Senate approach said they are concerned this will deemphasize programs they think are important but are not specifically addressed under the House approach such as youth-focused education campaigns, recovery support centers and programs to collect unused painkillers.

Consolidating programs under one funding umbrella “risks imbalance, as many states and localities seeking funding may only prioritize one or two of these activities,” Harm Reduction Coalition Policy Director Daniel Raymond wrote in a letter to House Judiciary Committee leaders.