PORTLAND (AP) – U.S. Rep. Tom Allen invited U.S. Sen. Susan Collins on Tuesday to join him at four town hall meetings next month to talk about key issues in their Senate race, but the Collins campaign said debates should be scheduled for the fall when voter interest rises.

In a “Dear Susan” letter, Democrat Allen suggested a string of evening meetings in Biddeford, Rockland, Ellsworth and Skowhegan to address concerns about energy and food prices, health care, Iraq and the economy.

“It is my sincere hope that your will join me in that conversation. There is simply too much at stake for Maine and our nation to wait until September and October for debates,” he wrote.

Collins spokesman Kevin Kelley said voters tend to pay more attention to political campaigns after Labor Day and the two campaigns are already scheduling debates for the fall.

“August is traditionally the month when candidates are on the campaign trail at fairs and festivals and community events, which is what Senator Collins has scheduled on her calendar,” he said.

In her “Dear Tom” reply, Collins said that “because of the lateness of your request, I will not be able to join you.”

Allen didn’t send a similar invitation to independent candidate Herbert Hoffman, whom Democrats are trying to keep off the ballot for fear that he will siphon votes from Allen.

In his response to Allen’s invitation, Kelley tweaked the congressman for his refusal to debate Tom Ledue, his opponent in last month’s Democratic primary.

“This is the same Congressman Allen who refused repeated requests to debate his primary challenger last spring, and now he says he welcomes a full debate while at the same time he and the Democratic Party are suing to silence the independent candidate in the race by having him removed from the ballot,” he said.

Allen spokeswoman Carol Andrews would not elaborate on Hoffman’s presence at the proposed series of town hall meetings. “We’re running against Susan Collins, so we invited Susan Collins,” she said.

Collins made it plain that she expects Hoffman to participate in the fall debates. In her reply letter, she told Allen she looks forward “to appearing with you and Herb” at those meetings.