* Gingrich, Santorum have agreed to Trump's plan
* Republican strategists warn candidates against debate
* Debate video on Newsmax.com
By Sam Youngman
WASHINGTON, Dec 6 U.S. Republican presidential candidate Mitt Romney said on Tuesday that he will not attend a controversial Dec. 27 debate to be moderated by real estate magnate Donald Trump, as have candidates Ron Paul and former Utah Governor Jon Huntsman.
Romney told Fox News' Neil Cavuto that he will not participate in the Iowa debate, which has drawn fire from Washington Republicans as well as two of Romney's competitors.
Some Republicans worry the showboating Trump, star of NBC's "The Apprentice" program, could make the event all about him rather than the candidates.
Speaking to reporters in Paradise Valley, Arizona, Romney said he was already participating in many debates.
"We've already set our calendar in December and I communicated to Mr. Trump that (the) schedule is completed," Romney said.
Trump flirted with a run for the Republican 2012 presidential nomination earlier this year and was derided for pushing a discredited charge that Democratic President Barack Obama might not have been born in the United States.
Romney said on the show that he had spoken with Trump and informed the multimillionaire businessman and entertainer that he will not attend.
Trump was characteristically prickly about Romney's decision.
"It would seem logical to me that if I was substantially behind in the polls especially in Iowa, South Carolina, Florida, I would be participating in the debate, but I can also understand why Gov. Romney decided not to do it," Trump said.
Iowa leads the state-by-state nominating contests with its Jan. 3 caucus, followed by January party primaries in New Hampshire, South Carolina and Florida.
The only candidates so far to agree to the debate are rising Republican Newt Gingrich and former Senator Rick Santorum.
A campaign spokesman for Texas Representative Paul said that Trump moderating a debate would result in "an unwanted circus-like atmosphere."
"The selection of a reality television personality to host a presidential debate that voters nationwide will be watching is beneath the office of the presidency and flies in the face of that office's history and dignity," campaign spokesman Jesse Benton said.
In the days following Trump's announcement of the debate, which will be co-hosted by Newsmax.com, a conservative news website, Republican strategists in Washington worried aloud that by participating in the debate, the Republican candidates would appear foolish or out-of-touch with voters.
Ari Fleischer, former press secretary for Republican President George W. Bush, said on Twitter that Trump's idea to moderate a debate is "absurd."
"I hope all GOP candidates turn him down."
And veteran Republican strategist Karl Rove has urged the Republican National Committee to call on Trump to cancel the event.
CORRECTED-Germany's Merck gets EU backing for oral MS drug
FRANKFURT, June 23 Germany's Merck KGaA has won a key recommendation to become a late entrant to the market for oral multiple sclerosis (MS) drugs in Europe, six years after its first attempt to launch the cladribine pill failed.