Republicans plan healthcare vote; Obama and TV host denounce bill

* Trump endorses bill, but it is unclear it can pass Senate

* Comedian Kimmel calls bill co-sponsor Cassidy a liar

* Group forecasts big federal funding cuts to states (Adds more senators undecided, Thune comment)

By Susan Cornwell and Susan Heavey

WASHINGTON, Sept 20 (Reuters) - Senate Republicans announced plans to vote next week on their latest bid to scuttle Obamacare even as a popular comedian who has become part of the U.S. healthcare debate denounced the bill and former President Barack Obama on Wednesday warned of "real human suffering."

President Donald Trump, who has expressed frustration at the Senate's failure thus far to pass legislation dismantling Obama's signature legislative achievement, said "47 or 48" Republicans back the bill, which needs 50 votes for passage in the 100-seat Senate, which his Republican Party controls 52-48.

"We think this has a very good chance," Trump, who made replacing Obamacare a top 2016 campaign promise, told reporters during an appearance with Egypt's president in New York.

Kentucky Senator Rand Paul opposes the bill. At least five other Republicans are undecided on it: Susan Collins of Maine, Lisa Murkowski and Dan Sullivan of Alaska, John McCain of Arizona and Jerry Moran of Kansas.

Republican Senator John Thune on Fox News said: “We’re a handful of votes short of having the 50 that we need."

As they worked to gather enough votes to win, after prior legislation failed in July, congressional Republicans and the White House were on the defensive after Jimmy Kimmel used his late-night TV show to blast the proposal and call Republican Senator Bill Cassidy, one of its two sponsors, a liar.

"This guy, Bill Cassidy, just lied right to my face," Kimmel said on his show on Tuesday night, referring to the senator who since May had touted a "Jimmy Kimmel test" of standards any Obamacare replacement would need to possess.

Senate Majority Leader Mitch McConnell, who was noncommittal on Tuesday about scheduling a vote, now intends to bring it to the Senate floor next week, said his spokesman David Popp.

Republicans are using the measure Cassidy is sponsoring with fellow Senator Lindsey Graham to make one last push this year to pass legislation to roll back the 2010 Obamacare law, a goal of theirs for seven years, facing a Sept. 30 deadline.

Avalere Health, a healthcare consultancy to hospitals and insurers, forecast that the bill would slash federal funding to states by $215 billion through 2026, with 34 states facing cuts.

Hit hard would be Democratic-governed California and New York, which expanded the Medicaid insurance program for the poor and disabled under Obamacare, while Republican-governed Texas, which did not expand Medicaid, would be a winner, Avalere said.