Gay marriage proponents in Washington state are backing the expansion of a domestic partnership law to give gay and lesbian couples all the benefits of marriage except the name.

At a Wednesday press conference, lawmakers, flanked by gay and lesbian couples, introduced the new bill.

The 110-page bill expands the coverage offered by its 2007 domestic partnership law to include all remaining areas currently only granted to heterosexual married couples, The Associated Press reports.

The bill is being sponsored by openly gay Senator Ed Murray, a Seattle Democrat who sponsored the state's domestic partnership law in 2007, while openly gay Rep. Jamie Pedersen (D-Seattle) is sponsoring the measure in the House.

Washington state lawmakers defined marriage as an institution between a man and a woman when it banned gay marriage in 1998. In 2006, the Washington Supreme Court upheld the legality of the law.

Last year, lawmakers successfully passed a bill that greatly expanded the partnership protections, moving from only 11 rights to over 170.

Public hearings on the so-called “everything but marriage” bill are scheduled to begin next week. Its sponsors say they have strong support for the bill with 20 senators and 60 representatives already singed on.

“I would say the most remarkable thing about this bill is that it is unremarkable,” Senator Ed Murray told The Associated Press. “Instead of the cultural wars that we have seen year after year, we see a Legislature that is mostly on board in moving forward on protecting all of Washington's families.”

But opponents to gay marriage have decried the measure, saying it approximates marriage.

“With this year's legislation, they are taking the final step to stitch together gay marriage in a state that does not legally permit it,” said Republican Senator Dan Swecker.

The state has licensed about 5,000 domestic partnerships since the law was enacted in July 2007.