Senate Minority Whip Harry Reid is threatening to block all of President Bush’s nonmilitary nominees, unless the White House allows the Nevada Democrat’s senior science staffer to be appointed to the Nuclear Regulatory Commission.

Reid’s action would be the second time in recent weeks that a Senate Democrat has put a blanket hold on White House nominations, further proof of the bitter partisan tensions between the two political parties.

Since Sept. 3, Sen. Mark Dayton (D-Minn.) has blocked all of Bush’s executive nominations except military nominees and promotions and nominations to the Homeland Security Department. Dayton could release his holds as early as Tuesday if he sees “adequate movement regarding the Minneapolis-St. Paul Airport noise abatement issue,” said Chris Lisi, a Dayton spokeswoman.

In Reid’s case, the White House rejected Greg Jaczko, the Nevadan’s appropriations director, for a seat on the five-member commission in April. This is the second time Bush has snubbed a nominee with ties to Reid.

In May, the administration rejected Reid’s son Leif for a U.S. District Court judgeship, even though the younger Reid’s name was forwarded to the White House by Sen. John Ensign (R-Nev.).

“In the interest of public safety, Senator Reid will hold up non-military nominees in order to move Dr. Jaczko’s nomination,” Tessa Hafen, a spokeswoman for Reid, said Monday.

The Nevada Democrat contends the nuclear energy industry convinced the White House to reject Jaczko in retaliation for his work to prevent Nevada’s Yucca Mountain from becoming the permanent repository for the nation’s nuclear waste. Congress approved Yucca Mountain as the repository in July 2002 over strong objections by the entire Nevada Congressional delegation, and the NRC will decide next year whether the site should be licensed.

“The White House must pick between a qualified candidate committed to public safety or political gamesmanship at the behest of big utility companies,” Reid said. “Dr. Jaczko is an eminently qualified scientist with a strong record of public service.

“Given Dr. Jaczko’s outstanding academic record, personal integrity and policy experience, I can see no good reason for the White House to reject him as the Democratic [nominee].”

A spokesman for the Nuclear Energy Institute, the industry’s trade group, said he is not aware that anyone within his organization spoke to the White House about Jaczko. But nonetheless, NEI spokesman Steve Kerekes said, they strongly opposed Jaczko joining the commission, which regulates the nuclear power industry.

“I think we would prefer to see someone who doesn’t come out of the Harry Reid school of styming Yucca Mountain and nuclear waste management progress,” said Kerekes. “Do we feel [Jaczko] is a wise choice? No. Does that carry weight at the end of the day? I have no idea — that is for the White House to say.”

Ashley Snee, a White House spokeswoman, said it is the administration’s policy not to comment on personnel matters.

But in a April 25 letter, the administration flexed its muscles by telling Senate Minority Leader Tom Daschle (D-S.D.) that Bush was rejecting his suggestion that Jaczko be nominated for the position, although no reason for doing so was offered.

“While the President welcomes the suggestions of the Congressional leadership for these positions as a matter of comity, ultimately the responsibility for nominations and appointments belongs to the President and he reserves his Constitutional authority to nominate or appoint persons other than those suggested by leadership,” wrote Dina Powell, assistant to the president for presidential personnel.

Instead, Powell suggested Daschle forward the name of another candidate to replace Jaczko, which the Minority Leader has refused to do. The issue smoldered over most of the summer and ignited when the White House nominated Vice Admiral John Grossenbacher for the other open seat on the commission. The White House sent Grossenbacher’s name to the Senate on July 25, right before the August recess. There are currently two openings on the five member commission.

“Senator Daschle feels that Dr. Jaczko is a fully qualified candidate for this position and stands by him as the nominee,” said Jay Carson, a spokesman for Daschle. “There is no credible reason for anyone to object to Dr. Jaczko’s nomination.”

But a Senate Republican leadership aide warned that if Reid puts a blanket hold on all of Bush’s nominees, it could have further repercussions.

“Reid needs to be careful because he is playing with fire,” said the GOP aide, speaking on the condition of anonymity. “This could come back and really, really hurt him in the future.”

A Democratic leadership aide scoffed at the GOP’s threat of retribution and echoed Daschle’s pledge that the Democratic Caucus would stand behind Reid.

“We will have the 41 votes and maybe more,” said the aide, noting that Reid has enough votes to filibuster any nominee.

Reid and Dayton are not the only Democratic Senators upset with the administration and GOP policies. Sen. Hillary Rodham Clinton (D-N.Y.) said this weekend she would prevent Utah Gov. Mike Leavitt (R) from becoming the new administrator for the Environmental Protection Agency, until the White House adequately answers questions of why the EPA failed to tell New Yorkers there were health risks associated with the air quality around the World Trade Center following the Sept. 11, 2001, terrorist attacks.

So far, Democrats have successfully blocked a handful of Bush’s judicial picks, most notably Miguel Estrada, who withdrew his name last week from consideration for a seat on the U.S Court of Appeals for the D.C. Circuit. Last year, Democrats blocked U.S. District Judge Charles Pickering from joining a different circuit court. Currently, Democrats are blocking Texas Supreme Court Justice Priscilla Owen and Alabama Attorney General William Pryor, both of whom have been nominated for separate circuit court judgeships.