By Jason McLure

LITTLETON, New Hampshire (Reuters) - Presidential hopeful Jon Huntsman has waded into a dispute over the Republican primary calendar, saying he will boycott the Nevada caucus unless the state postpones its balloting to give New Hampshire more space.

Huntsman's campaign accused Republican frontrunner Mitt Romney of pushing Nevada to select an early date, as a way of consolidating his lead.

Nevada has tentatively jumped its caucus ahead to January 14, and with Iowa eyeing January 3 for its first in the nation caucus, New Hampshire election officials feel boxed in.

The state jealously guards its position of holding the first primary and the second contest overall in the presidential nominating race, behind the Iowa caucuses.

But Nevada and other states have moved their contests forward, threatening New Hampshire's status.

Huntsman, the former Utah governor, is polling seventh nationally in the Republican race to challenge Barack Obama in the 2012 election.

But he is doing better than that in New Hampshire. He has concentrated his efforts there and his campaign has said a strong showing in the Granite State would give him a critical boost for the contests that follow.

"The Huntsman campaign will boycott the Nevada caucus as long as the state continues to jeopardize New Hampshire's primary date," Huntsman campaign manager Matt David said in an e-mail.

"We call on the other campaigns to join us, especially Governor Romney's campaign given their involvement in moving Nevada's date forward."

Romney's campaign rejected Huntsman's challenge.

"It is up to each state to determine the date of their primary or caucus, and Gov. Romney has consistently supported Nevada's status as an early nominating contest that follows New Hampshire," said Romney spokesman Ryan Williams.

New Hampshire's secretary of state threatened on Wednesday to hold its primary as early as December 6 if Nevada refused to yield. A spokesman for Nevada's Republican Party, which sets the caucus date, did not immediately respond to messages.

Huntsman, who has presented himself as a moderate alternative to Romney, is polling as high as fourth in the New Hampshire and campaigning heavily.

A December date "would certainly hurt someone like Huntsman because he really needs more time," said Dante Scala, political scientist at the University of New Hampshire.

"He's been working a grassroots strategy. He needs to hold several dozen more town hall meetings."

(Editing by Ros Krasny and Jerry Norton)