By Susan Cornwell

WASHINGTON (Reuters) - Democratic lawmakers on Thursday ended a daylong protest in the U.S. House of Representatives to protest the lack of action on gun control and Congress looked unlikely to approve meaningful firearms restrictions in the wake of the Orlando, Florida, massacre.

Democratic house members started a sit-in on the floor of the House on Wednesday, chanting and singing, and stayed all night to push for gun control legislation after this month's shooting at a gay nightclub in Orlando, which killed 49 people. Republicans, who hold a majority in the House, adjourned the chamber and went home for a holiday break.

Representative Steny Hoyer, the No. 2 Democrat in the House, told Reuters that lawmakers would now go back to their home districts to try to build support for legislation.

As the protest ended, the chances of gun legislation immediately after Orlando appeared to be worsening.

In the Senate, Republicans aimed to vote on Thursday on whether to derail bipartisan compromise gun control legislation that has been under negotiation for several days, Republican Senator Bob Corker told reporters.

Dramatic tactics by legislators are rare in the U.S. Capitol and the protest underscored how sensitive the gun control issue has become after the massacre in Orlando where a U.S.-born gunman pledging allegiance to Islamic State killed 49 people.

The House Democrats were seeking votes on legislation to expand background checks for gun purchases, as well as measures to curb the sale of weapons to people on government watch lists.

Congress has not passed major gun control legislation since 1994, with gun rights defenders saying such measures infringe the constitutional right to bear arms.

"We must keep the faith and we must come back here ... more determined than ever before," said Representative John Lewis, a Democrat from Georgia and a key figure in the civil rights protests of 1960s, who led the House sit-in.

(Additional reporting by Richard Cowan, Timothy Ahmann, Timothy Gardner and Eric Walsh, Doina Chiacu, writing by Alistair Bell; Editing by Bill Trott)