WASHINGTON — Efforts in the House to delay increases in federal flood insurance premiums face determined opposition from watchdog groups that say taxpayers shouldn’t have to subsidize coverage for homeowners who build or buy in high-risk areas.

Steve Ellis, vice president of Taxpayers for Common Sense, said if the final language in the House bill ends up similar to a bill the Senate passed, “we’d come out swinging.”

House leaders plan to bring a bill up for a vote this week.

“We would work to try to stop the bill if it’s not a responsible approach,” Ellis said. “You would have an irresponsible approach from the Senate trying to marry with a separate, but equally irresponsible approach in the House.”

The Senate measure proposed by Democratic Sen. Robert Menendez of New Jersey and Republican Sen. Johnny Isakson of Georgia — and backed by Mississippi Sens. Thad Cochran and Roger Wicker — would benefit some homeowners with policies through the National Flood Insurance Program by delaying their premium increases for four years. During the delay, the Federal Emergency Management Agency would complete a study of how to make the higher rates affordable.

Efforts to pass the legislation in the House have gained more support in recent weeks.

The rate increases were created under the Biggert-Waters Flood Insurance Reform Act of 2012. The reforms, overwhelmingly supported by lawmakers, were intended to help make the government’s flood insurance program financially solvent by bringing rates in line with true flooding risks.

The program, which is $24 billion in debt, insures more than 5.5 million residential and commercial policyholders, according to FEMA.

Some House Republicans say the rate increases are needed to move the National Flood Insurance Program closer to solvency.

Watchdog groups say more fiscally responsible solutions include providing mitigation assistance, phasing in rate increases, offering temporary premium assistance for low-income homeowners and fixing errors in flood maps.

The groups oppose what they call “unjustifiable relief” for vacation homeowners and those living in areas that repeatedly flood.

“We would oppose such a scheme strongly,” said Andrew Moylan, a senior fellow at the R Street Institute, which describes itself as a libertarian think tank. “What that does is effectively gut a bill (Biggert/Waters) that over 400 members of the House of Representatives voted for 18 months ago.”

House Majority Leader Eric Cantor of Virginia said earlier this month the House will consider a “modified” version of the Senate bill when lawmakers return to Washington this week.

“The Senate bill irresponsibly removes much-needed reforms and imposes additional costs on taxpayers,” he said in a statement. “The House will act to protect the flood insurance program but also protect homeowners from unreasonable and unrealistic premium increases.”

By Friday, lawmakers had not finalized language in the House bill.

“We need a Goldilocks solution — one that is just right and provides both relief and reforms for primary homeowners and real estate markets in communities across the country,” said GOP Rep. Steven Palazzo of Mississippi, vice chairman of the Home Protection Caucus.

House lawmakers are weighing whether to introduce stand-alone legislation or amend a bill by Reps. Michael Grimm, R-N.Y., and Maxine Waters, D-Calif., that is similar to the Senate measure.

Under the Senate measure and the Grimm-Waters bill, the delay in premium increases would be retroactive to Oct. 1, although neither bill specifies how or when that would be implemented, and neither contains a provision to issue refunds.

Lawmakers are considering a number of options, including repealing a provision in the Biggert-Waters law that increases premiums when FEMA adopts new flood maps. The provision increases premiums up to the full-risk rate over five years.

Last summer, the House approved a measure proposed by Cassidy that would delay rate hikes by a year. FEMA recently announced delays for nearly two years through 2016.

Another proposal would allow homeowners buying a house already covered under the National Flood Insurance Program to receive the subsidized rate.

The bill would be paid for through small assessments on all policy holders. The money would go into a reserve fund for FEMA to pay future claims.

Administration officials have raised concerns about delaying rate increases, saying that would erode the flood program’s finances and make it more difficult for FEMA to pay future claims. But they’ve said they will work with Congress to make sure “economically distressed policyholders” aren’t “unduly burdened.”

A White House official confirmed last month that President Barack Obama would sign legislation to delay the increases.

It’s an issue that resonates in states where several lawmakers, including Landrieu and Cochran, are running for re-election. Cassidy hopes to unseat Landrieu. Cochran faces a challenge from GOP state Rep. Chris McDaniel.