Will he or won’t he? Vice President Dick Cheney is one of the nation’s most prominent Republicans, but there are doubts about whether he will attend the GOP convention.

Cheney press secretary Megan Mitchell left the question open on Tuesday, saying Cheney’s schedule has not been set for September. Delegates are scheduled to meet in St. Paul, Minn., on Sept. 1-4., to nominate Arizona Sen. John McCain for president.

Separately, at least five Republican senators have decided to skip the GOP convention.

Sens. Gordon Smith of Oregon, Elizabeth Dole of North Carolina and Susan Collins of Maine all face tough re-election campaigns. Two others, Wayne Allard of Colorado and Larry Craig of Idaho, are retiring.

Smith, a two-term Republican, aired an ad in June touting his work with Democratic presidential candidate Barack Obama on fuel efficiency standards. Last month another Smith ad cited his work with John Kerry, the 2004 Democratic nominee for president, on legislation to protect homeowners against foreclosure.

Matt Canter, a spokesman for Oregon House Speaker Jeff Merkley, Smith’s Democratic opponent, called the latest ad “an attempt to distract from his record of supporting George Bush 90 percent of the time.”

Smith’s spokeswoman, Lindsay Gilbride, said Tuesday that Smith will campaign in Oregon during the convention and that his absence doesn’t indicate a lack of support for McCain.

Collins’ spokeswoman Jen Burita said she will be campaigning in Maine.

It would be highly unusual for a sitting vice president to skip his party’s nominating convention. For the last 32 years the vice president has been either renominated for that job or nominated for president.

Cheney has low approval ratings and is widely regarded as a secretive, behind-the-scenes power broker. But his approach plays well to conservatives. The White House has to calculate whether Cheney would help or hurt Sen. John McCain’s campaign for the presidency.

President Bush will deliver a speech on the first night of the convention and then leave, turning over the spotlight to McCain.

Democrats are working hard to link McCain to Cheney, mindful of his unpopularity with the general public and his villain-like status among their party’s rank and file. On Tuesday, Democratic candidate Barack Obama linked the nation’s energy problems to Cheney and contended that McCain was following “the Cheney playbook.”

The DNC rolled out a new Web site on Tuesday called “The Next Cheney.” It assails McCain’s potential vice presidential picks and links each to Cheney.

McCain is quoted on the page as saying to Cheney in 2001, “With a little more luck, I might have been able to ask you to be my vice president.”

Even vice presidents not receiving a nomination have attended their party conventions in recent political history.

In 1976 President Gerald Ford chose Sen. Bob Dole of Kansas, not Vice President Nelson Rockefeller, as his running mate. Rockefeller, who had been appointed to a position he no longer wanted, still appeared at the convention, nominating Dole.

Nearly 24 years earlier, in 1952, Vice President Alben W. Barkley abandoned a bid to succeed President Harry Truman but still addressed delegates, who gave Barkley a wild ovation.