With the U.S. Senate campaign in its final six weeks, both Chellie Pingree and Susan Collins continue to debate how many debates are needed and how they are to be structured.

While Democratic challenger Pingree wants a whole host of debates on a number of specific issues, the Republican incumbent Collins is satisfied with taking part in seven debates and public forums that already have been scheduled.

The disagreement came to a head last week when the Pingree campaign accepted invitations to 14 candidate forums and debates, then chided Collins for restricting her appearances to half that many. The most recent poll has Pingree trailing by double digits, and frequent debates are viewed as one way to boost her campaign and expand her message.

“You will find in just about any political race that the front-runner wants to have fewer debates and the challenger, especially if trailing in the polls, wants to have more debates,” University of Maine political science professor Richard Powell said Monday. “It make a great deal of sense for Pingree to want as many debates as possible. It can only be neutral or work to her advantage.”

For Collins, on the other hand, a stumble or gaff in a debate could be devastating.

“She has the most to lose,” he said.

Collins has insisted that her work in the Senate prevents her from returning to Maine to take part in a wide range of debates. The Senate is scheduled to adjourn by the middle of October. Other than appearances in Maine on weekends, Collins has been adamant about staying in Washington as long as Congress is in session.

Beginning Oct. 19, Collins and Pingree are scheduled to participate in three televised debates; three forums before chambers of commerce in Bangor, Portland and Lewiston-Auburn; and one radio debate in the final weeks of the campaign.

“I think agreeing to seven debates, or joint appearances if you will, far exceeds anything the Pingree campaign expected we would do,” Collins communications director Felicia Knight said Friday. “We’re more than happy to have a fair, full and unfettered exchange of ideas.”

Pingree spokesman Deborah Barron observed that while the campaign welcomed Collins’ decision to debate, Pingree was concerned that the public would be denied the opportunity to gauge the candidates’ positions on specific issues without more appearances. She criticized Collins for declining to take part in single-issue debates on education, health care, corporate responsibility, social security and the environment.

“This is a wonderful first step, and we’re happy that the public pressure to debate forced her to do something. We’re happy that she’s agreed to three televised debates, but she should move beyond her chamber-of-commerce comfort zone,” Barron said Thursday. “Forums at the chamber of commerce are not the same thing as substantive issue debates.”

Barron stressed that Collins turned down invitations by such broad-based organizations as the League of Women Voters, the Maine Leadership Consortium, and Consumers for Affordable Healthcare.

Knight emphasized the television debates would likely cover a wide range of issues. She said the chamber of commerce debates would be held in the state’s three largest cities and should be free-flowing as well.

Knight downplayed Collins’ decision not to engage in further joint appearances, suggesting instead that the clamor for more debates indicated that the Pingree camp was grasping at this point in the campaign. She speculated that recent polls showing Collins with a commanding lead over Pingree could be behind the call for more debates.

“I think this is just amateur hour in the Pingree campaign. They never thought we would agree to debates and now that we’ve agreed to seven, they keep asking for more,” said Knight. “This is the Pingree campaign just coming unglued at this point. … I think this is a pure illustration that they are tripping all over themselves and don’t know what to do next.”

Professor Powell said Pingree could reap public-relations points by painting Collins as unwilling to debate a broad range of issues and speculated that there could be “a significant amount of pressure for Collins to engage in debate” in coming weeks. More debates would provide Pingree with an opportunity to address the core issues of her campaign, he said.

Powell cautioned that political camps have been known to miscalculate on debate strategy. He said one needs only to look back to the 2000 presidential election to see how conventional wisdom was turned on its head.

In that campaign, Al Gore was presumed to be the more skillful debater while the abilities of George Bush were thought to be questionable. However, when the debates took place, it was Bush who got a huge push from his performance and Gore who revealed aspects of his personality that proved damaging.

“These things don’t always play out in the way you expect them to,” he said.