BOSTON -- The Legisalture is advancing a $1.1 billion spending bill to cover COVID-19 response costs, while the House is walking back its earlier support for an increase in road and bridge maintenance funding amid stalled tax-raising talks and a budget crunch prompted by the pandemic.

Ways and Means Committee chairs in both branches announced joint support Monday for their version of a supplemental budget, adding $100 million and more specific spending requirements to a bill that Gov. Charlie Baker said would allow Massachusetts to seek reimbursement for pandemic spending from the federal government.

The House also approved legislation Monday that would direct $200 million to the so-called Chapter 90 program, which reimburses cities and towns for local road and bridge repairs.

The amended bill (H 4326), which earned unanimous endorsement from the House Ways and Means Committee before being engrossed at Monday's session, effectively seeks to trim a third of the spending off the $300 million both branches have already approved.

State leaders have kept the annual appropriation toward Chapter 90 at $200 million for years, albeit with occasional supplemental funding added, despite calls from municipalities for significant increases.

In March, one day after approving more than half a billion dollars in tax and fee increases, the House included $300 million for the program in its version of Gov. Charlie Baker's $18 billion transportation borrowing bill.

The Senate also approved a $300 million funding level this month, but because it left untouched the revenue package, House leaders began to question the added investment.

"We did a bill in March, obviously, and we increased Chapter 90 at that point in time, but we had a way to pay for it," Rep. Aaron Michlewitz, chair of the House Ways and Means Committee, said this month. "We had mechanisms to pay for it. We're in the midst of dealing with potentially $6 to $8 billion dollars in a shortfall of revenue for (fiscal year) 2021, so it's a little perplexing to figure out how we're going to be doing that and raising Chapter 90 without using the revenue sources that have been put out there by the House."

Antonio Caban, a spokesperson for Senate President Karen Spilka, told the News Service on Monday that Senate leaders "absolutely think that $300 million is affordable" based on existing revenues.

Baker has also supported funding the program at $200 million for fiscal year 2021, including that amount in his original version of the legislation and in the administration's fiscal 2021 capital investment plan unveiled last week.

The House advanced the COVID-19 spending bill Monday and is expected to consider it further on Wednesday.

Baker filed the original $1 billion supplemental spending legislation (H 4707) on May 12, saying at the time that all of the appropriations it covers would be reimbursed by the federal government.

His proposal called for a lump sum and did not outline specific uses for the money beyond responding to COVID-19, but the Legislature added 17 pages and greater specificity to the version approved Monday.

Among a range of spending mandates, the Ways and Means Committee rewrite (H 4802) requires directing at least $350 million to the purchase of personal protective equipment, $139 million for rate add-ons to congregate care and other human service providers, $111.4 million in supplemental payments to hospitals and health care providers, $44 million on the state's contact tracing program, $36 million on emergency child care, and $45.6 million on early education grants.

The updated version of the bill also adds $100 million in spending authorizations through the end of fiscal year 2021 to cover monitoring, treatment, containment and prevention of COVID. That batch of funding would direct at least $20 million to emergency housing aid, $12.3 million to early intervention telehealth services, and millions more to food assistance.

Democratic leaders in the chambers collaborated on the legislation before it emerged Monday. In a joint statement before either vote, Michlewitz and Senate Ways and Means Committee Chair Sen. Michael Rodrigues said the proposal responds to an "unprecedented fiscal challenge."

"The priorities included within this supplemental budget -- funding for personal protective equipment, emergency child care, health care supports for community health centers and behavioral health services, housing and homelessness supports, and food security -- reflect the advocacy of the members of both chambers to urgently address the challenges facing our Commonwealth during this difficult time," they said.

Money is on the table through the Federal Emergency Management Agency and other federal programs to relieve COVID-response costs, but Baker has said states cannot access the funding until they authorize spending at their level and then submit for reimbursement.

FEMA received $45 billion to distribute, and the governor warned last week that Massachusetts faces a risk of being locked out until the agency gets a new round of funding if legislative leaders do not act soon.

"Until there's an authorization to create a so-called 'state spend' to be reimbursed, the clock's ticking," Baker said at a Wednesday press conference. "Other states are chasing this, and I worry a lot about how long the federal resources are going to be there to actually get reimbursed in a reasonable period of time."

Baker's separate interim fiscal 2021 budget bill (H 4806), authorizing $5.25 billion in spending while legislative leaders continue to deliberate a plan for the fiscal year that starts July 1, was fast-tracked by the House and Senate Monday and needs only an enactment vote in the Senate Thursday to reach the governor.

Sam Doran and Chris Van Buskirk contributed reporting.