The court set further hearings on the charge against Bruce Carson for Oct. 17 and 22, but a trial is not likely to be held before next year.
An RCMP investigation began after the Prime Minister's Office contacted police in March 2011 with allegations Carson had illegally lobbied the federal government.
Carson, 66, is charged with one count of fraud on the government, also known as influence peddling.
Lawyer Pat McCann maintains his client — an adviser to Harper from 2006 to 2008 — will vigorously defend himself.
"The allegations are pretty marginal," McCann said Monday.
The Oct. 17 session will be a closed pre-trial conference to sort out logistics, while the trial date may be set at the Oct. 22 hearing.
The trial, expected to last about a week, is likely to be held some time next year, McCann said.
The Aboriginal Peoples Television Network first raised concerns about possible impropriety, reporting that Carson had allegedly lobbied Indian and Northern Affairs on behalf of an Ottawa-based water company that employed his girlfriend.