WASHINGTON (Reuters) - Senate Democrats reacted with anger and derision on Tuesday to a Republican tax bill unveiled late Monday night without warning by the top tax law writer in the U.S. House of Representatives, just days before it was expected to be voted on by the House.

FILE PHOTO: Sen. Ron Wyden (D-OR) speaks during a markup on the "Tax Cuts and Jobs Act" on Capitol Hill in Washington, U.S., November 15, 2017. REUTERS/Aaron P. Bernstein

The 297-page bill, which House tax committee Chairman Kevin Brady described as a “bipartisan” measure, includes energy-related tax credit extensions, technical fixes to last year’s Republican tax overhaul, changes to retirement and savings rules and an overhaul of the Internal Revenue Service.

An initial vote on the measure was expected as early as Thursday in the House, where Republicans likely will have enough votes for passage, according to analysts.

In the 100-seat Senate, where the bill would need 60 votes to advance, its outlook was unclear in a truncated “lame duck” session of Congress, with hard feelings among Democrats who say they first heard about the measure in media reports.

“When the other side essentially learns about it for the first time in the press, which was last night, it is invariably messaging and gamesmanship,” Senator Ron Wyden, top Democrat on the tax-writing Senate Finance Committee, told reporters.

“Using the media as a middleman to distribute their tax proposals didn’t get the Republicans bipartisan support for their tax ideas in 2017. And I don’t think it’s going to help them now,” he added.

Senator Mark Warner, another Senate Finance Committee Democrat, dismissed the legislation as “that imaginary bill”, telling reporters on Capitol Hill that he had seen no specifics.

U.S. voters ended Republican control of the House in the Nov. 6 elections and handed majority power to the Democrats. Brady is expected to be replaced as tax committee chairman in January by Democratic Representative Richard Neal.

In the interim, Congress is holding a short, “lame duck” session until mid-December in which Republicans, including Brady, remain in charge of the House agenda.

House and Senate Democrats said they were reviewing the legislation and acknowledged that parts of it, including provisions to allow retirement savings by seniors, could find bipartisan backing. But it was unclear whether congressional rules would allow lawmakers to cherry-pick the more popular measures.

Brady, chairman of the tax-writing House Ways and Means Committee, released the bill, saying it had support from both parties and would see swift House action.

A House Democratic aide dismissed Brady’s claim that the measure was bipartisan, though some sections of it appeared to be based on previous bills with Democratic cosponsors.

Senate Finance Committee Chairman Orrin Hatch, a Republican, welcomed Brady’s legislation and said he would consult other members of his panel about possible next steps.

But other priorities could be a problem for the package as senators try to break for the year by Dec 7.

The bill covers tax breaks for fuel cell cars, energy-efficient homes, race horses, mine safety equipment, auto racetracks and many other items, as well as retirement savings plans such as 401(k)s and individual retirement accounts (IRAs).

It also includes “technical corrections” to sweeping tax overhauls that Trump enacted in 2017, Brady said in a statement.