The chief House architect of a Postal Service overhaul that failed to gain traction in the last Congress is back with new draft legislation that would allow the financially ailing agency to move to five-day delivery and ban it from entering no-layoff agreements with employees.

To broaden support for a bill criticized by Democrats as too partisan and anti-labor, House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.) is attempting to soften opposition with his new proposal, released Thursday. It would allow the Postal Service to scrap an annual $6 billion payment to pre-fund health costs for future retirees, a major concession that is likely to help the bill’s chances in the Senate.

The pre-funding requirement and plummeting mail volume pushed the mail agency into a $15.9 billion deficit in the past year alone, and postal officials have warned that they will default on a third pre-funding payment this year.

But Issa’s new draft also keeps proposals that have divided lawmakers. Democrats are likely to oppose any language allowing layoffs, and members of both parties who represent rural districts have pushed back against five-day delivery.

An immediate switch to five-day service, for example, was not in legislation the Senate approved last year. Issa’s bill did not receive a vote on the House floor.

The legislation also would require the Postal Service to move aggressively to halt curbside delivery of the mail in favor of post office boxes or clustered boxes on street corners, a change that Issa says could save at least $4 billion annually but that unions oppose.

“Right now the Postal Service is hurtling toward complete insolvency,” says a fact sheet on the draft bill. “If USPS cannot pay its bills, the American taxpayers will almost certainly be asked to pick up the tab.

“This plan will give the Postal Service new tools to cut costs and restructure its finances, while ensuring it has the capital necessary to do so.”

The National Association of Letter Carriers said the bill contains “many of the damaging and fundamental flaws” in Issa’s previous bill. The letter carriers and other postal unions say eliminating a day of mail delivery would slash jobs, and they oppose a provision to shrink curbside service as a threat to mail security.

“The NALC is disappointed that Chairman Issa did not take a fresher approach to postal reform with this discussion draft,” the union’s president, Fredric V. Rolando, said in a statement.

As before, the legislation would create a panel modeled on the D.C. Financial Control Board to oversee postal operations, with a broad mandate to reduce costs and bring the agency back to financial solvency. It would replace the current Board of Governors until postal finances are in the black.

The new plan scraps a system modeled after the military’s Defense Base Closure and Realignment Commission — and opposed by postal officials — that would have allowed a separate board to decide which post offices and mail-sorting hubs should close. The agency has moved to downsize on its own in the past year, shortening hours at thousands of local post offices and consolidating sorting hubs across the country.

Issa’s Postal Reform Act of 2013 will not be formally introduced for months, congressional aides say. By circulating a long-awaited draft, they say, Issa hopes to work with labor, rural lawmakers and groups that opposed his effort in the last Congress.

The draft comes on the heels of a failed attempt by Postmaster General Patrick R. Donahoe to drop Saturday mail delivery without congressional approval. Donahoe said he was acting in desperation because Congress has not approved a restructuring plan.

But Donahoe was forced to back down after lawmakers objected. Issa would allow him to move forward with five-day delivery of letters and second- and third-class mail but continue delivering packages six days for at least five years.

Postal Service spokesman David Partenheimer said officials are reviewing the proposal. In the past, Donahoe agreed with some provisions in Issa’s bill; he and his predecessors proposed for years eliminating Saturday delivery.

But Donahoe has opposed regulation by a new entity.

Issa and other key lawmakers on postal issues, including Sen. Thomas R. Carper (D-Del.), chairman of the Senate Homeland Security Committee, and Rep. Elijah E. Cummings (Md.), ranking Democrat on Issa’s panel — have pledged to reach agreement on a restructuring plan in this Congress.

Carper applauded Issa for releasing a proposal but acknowledged that the lawmakers still have differences.

“While we differ in our approach in some areas, Chairman Issa and I, and the rest of our colleagues, are united in our effort to restore the Postal Service to solvency and give it the tools it needs to thrive in the years to come,” Carper said in a statement.