WASHINGTON — House Republican leaders are supporting a bill to encourage stem-cell research that uses blood from umbilical cords. The measure offers an alternative to spending government money for research that would destroy human embryos.

House Speaker Dennis Hastert, R-Ill., had agreed earlier to allow a vote as soon as next week on a bill by Reps. Mike Castle, R-Del., and Diana DeGette, D-Colo., to lift President Bush's 2001 ban on the use of federal dollars for research using any new embryonic stem-cell lines.

But after Castle and other moderate Republicans angered conservatives by sponsoring polls in their districts on the issue, Hastert and Majority Leader Tom DeLay, R-Texas, said they would pair the bill with a separate measure to encourage stem-cell research that uses umbilical-cord blood.

DeGette yesterday said the GOP leaders' plan was "a weak attempt to divert support from our bill."

"The bills are completely compatible," she said. She said she intends to vote for both measures and will encourage other members to do the same.

Supporters of embryonic stem-cell research, including Nancy Reagan, say it could lead to cures for Alzheimer's, Parkinson's and other degenerative brain and nerve diseases. Opponents say taxpayers should not be forced to pay for such research when large numbers of them think the resulting destruction of the embryo is immoral.

Cord-blood cells are similar to embryonic cells but can grow into fewer types of tissues. Extracting stem cells from cord blood does not require the destruction of an embryo.

"There are some members who might be more inclined to vote no on Castle if they can vote yes on the cord-blood bill," said Rep. Dave Weldon, R-Fla..

The effort to provide undecided members an option more agreeable to anti-abortion groups jeopardizes the momentum that the Castle-DeGette measure acquired after President Reagan's death last June and the Terri Schiavo right-to-die case this year. Supporters claim to have about 200 co-sponsors in the 435-member House and commitments from enough other members to garner the 218 votes needed to pass it despite a White House-promised veto.

A rare split appeared in the House GOP caucus when Weldon and others said some sponsors of the Castle-DeGette bill helped finance a poll by the Winston Group in the districts of fellow Republicans showing that opposing the bill might prove unpopular back home.

The survey of 1,300 registered voters — about 100 in each of 13 districts — asked respondents for their views on embryonic stem-cell research, according to the firm's spokeswoman, Amy Hopcian. Of those polled, 66 percent favored stem-cell research, 27 percent opposed it and the rest were undecided.

The poll so infuriated Rep. Rick Renzi, R-Ariz., that colleagues had to pull him away from "a heated discussion" with Rep. Mark Kirk, R-Ill., who supports the bill, according to Hill staff members and a report in the newspaper Roll Call.

In another development:

Massachusetts lawmakers yesterday rejected Gov. Mitt Romney's amendments to a stem-cell-research bill, including a proposed ban on using cloned embryos for the purpose of obtaining stem cells to use in treating disease.

Another of the rejected changes would define the beginning of life as the moment of conception; the bill defines it as the moment an embryo is implanted in the womb.

The Republican governor, who supports research using adult stem cells or leftover frozen embryos from fertility clinics, wanted to ban scientists from creating a cloned embryo to harvest stem cells to use to create tailor-made genetic cures.

The bill allows the practice, known as therapeutic cloning.

Opponents of the changes said that the proposed revisions would gut the bill and that embryonic stem-cell research could transform Massachusetts into a center for cutting-edge research into the cure and treatment of spinal-cord injuries, diabetes and Parkinson's disease, among other illnesses.

Both chambers approved the legislation earlier, but Romney sent it back last week, vowing not to sign it into law if his amendments weren't accepted. The original legislation was sent back to Romney last night.

Material from The Washington Post is included in this report.