OTTAWA -- With his folksy style and passion for politics, Mike Duffy became a household name as a veteran television journalist -- a career that led him to a coveted Conservative seat in Parliament's upper chamber.

All that came crashing down Thursday -- at least for the foreseeable future -- as the RCMP laid 31 charges of fraud, breach of trust and bribery against the suspended senator.

The charges involve Duffy's claims for living expenses, claims for travel expenses unconnected with Senate business and fraudulent contracts, said RCMP Assistant Commissioner Gilles Michaud.

They also cover a $90,000 payment Duffy allegedly received from Nigel Wright, the prime minister's former chief of staff.

Convictions on the charges could result in a prison sentence. The bribery count carries a maximum of 14 years.

Duffy's first court appearance is set for Sept. 16, the day after Parliament is scheduled to resume.

The charges reignited a smoldering scandal over Senate expenses that has also ensnared Conservatives Patrick Brazeau and Pamela Wallin -- now suspended Independents -- as well as Liberal Mac Harb, who resigned.

Prime Minister Stephen Harper appointed Duffy, Brazeau and Wallin to the Senate but has tried to distance himself from their actions and those of Wright, who gave Duffy the $90,000 to cover expenses.

The behaviour outlined in the RCMP charges against Duffy is "disgraceful," a Harper spokesman said Thursday.

"We assisted the RCMP throughout their investigation, and congratulate them on the progress they have made," Jason MacDonald said in a statement.

"Those who break the rules must suffer the consequences. The conduct described in the numerous charges against Mr. Duffy is disgraceful."

"As this is now a criminal matter that is before the courts, we have nothing further to add."

The opposition, meanwhile, blamed the charges on Harper, who named Duffy to the red chamber in 2009.

"These charges and the scandal stem from the poor judgment of the prime minister," said New Democrat MP Nycole Turmel. "The buck stops with Stephen Harper."

Liberal MP Marc Garneau echoed the criticism.

"These charges are extremely serious," Garneau said. "Mike Duffy is a legislator in Canada's Parliament and the prime minister of this country is the one who put him there."

"Throughout this entire PMO ethics scandal, the prime minister has tried to evade responsibility."

The charges cover more than $200,000 in allegedly phoney expenses, Michaud said.

They include money the P.E.I. senator claimed for living expenses on what he said was a secondary residence in Ottawa, as well as expenses he charged for travel on personal or political business.

The bribery charge covers the $90,000 payment from Wright.

The RCMP's investigation of Duffy, which is now complete, began with a look at housing expense claims, Michaud told a news conference.

Investigators pored over four years' worth of expense claims, bank statements, phone records and thousands of emails, he said. They interviewed witnesses from British Columbia, Saskatchewan, Ontario and Prince Edward Island.

The probe ended up taking four different paths.

The first involved expense claims relating to Duffy's secondary residence in Ottawa, while the second covered the filing of Senate expense claims for travel for personal and partisan reasons, unrelated to Senate business.

A third avenue covered consulting contracts awarded over a four-year period and the use of part of those funds for personal gain or for expenses beyond the reach of Senate oversight.

The final one involved the $90,000 Duffy got from Wright to repay his residency expense claims.

The RCMP said in April that Wright would not be charged.

Wright said at the time he intended to secure the repayment of taxpayer funds, and that he believed his actions were lawful and in the public interest.

Wright had no comment on Thursday's developments, said Guy Giorno, a member of his legal team.