Just 13 per cent of Canadians believe Prime Minister Stephen Harper is telling the truth when he says he had no knowledge of Nigel Wright鈥檚 $90,000-bailout of Sen. Mike Duffy, according to a new poll.

The 麻豆影视 Ipsos Reid poll also found that 44 per cent were 鈥渘ot sure whether or not the prime minister had any knowledge of the monetary gift made by Mr. Wright at the time,鈥� and 42 per cent said they are 鈥渃onvinced that the prime minister would have known about the monetary gift by Mr. Wright at the time.鈥�

In a sign of how politically damaging the scandal could be, the survey also found that 66 per cent of respondents considered the involvement of the Prime Minister鈥檚 Office a 鈥渟erious ethical breach.鈥�

The remaining 34 per cent said it 鈥渞epresents a relatively minor issue that says little about the ethical fitness of the Prime Minister and his government鈥檚 fitness to govern Canada.鈥�

The poll was conducted on May 27 and 28 and included an online panel of 1,009 respondents. The results are considered accurate within +/- 3.5 percentage points.

When asked what should happen to senators who were found to have violated expense policies, 23 per cent said it鈥檚 possible that they made 鈥渃lerical mistakes鈥� and should be allowed to pay back ineligible expenses and remain a senator. However, 77 per cent said no matter their 鈥減ersonal excuses,鈥� if they are found to have breached expense policies, they 鈥渟hould resign from the Senate.鈥�

A whopping 92 per cent of respondents either strongly or somewhat support requiring senators and MPs to post expense reports, with receipts, online.

Meanwhile, when asked about the fate of the Senate:

  • 43 per cent said it should 鈥渂e done away with completely,鈥� up seven points from February.
  • 45 per cent said it should 鈥渂e reformed to make it, for example, an elected body,鈥� up three points.
  • 13 per cent said the senate should be 鈥渒ept as is,鈥� down nine points.

RCMP investigation

The vast majority of Canadians want either an RCMP investigation or a public inquiry into the ongoing Senate expense scandal, and felt that senators should not be left to handle the probe themselves.

The survey found that 44 per cent of respondents think the RCMP should lead an investigation, while 31 per cent called for a public inquiry led by a judge.

Only 6 per cent said the Senate itself should lead an investigation, while 12 per cent said the House of Commons Ethics Committee should be tasked with the job.

One in 10 respondents said they believe the issue should be dropped and no investigation should be carried out 鈥渂ecause it is not really a big deal.鈥�

The Senate鈥檚 internal economy committee revisited the issue of senators鈥� expense claims amid ongoing questions about sanitized audit reports, expenses billing, and what Harper knew of a $90,000 cheque his chief of staff wrote to help Sen. Mike Duffy repay ineligible expenses.

The cheque is also the subject of an investigation by Canada鈥檚 Ethics Commissioner, Mary Dawson. The RCMP has also requested a number of documents in connection with Senate expense claims.

The opposition has hammered the prime minister about the expense scandal during question period in the House of Commons this week, trying to determine what Harper knew and when he knew it.

Harper insists he knew nothing of the cheque until Wright informed him about it on the morning of May 15. Duffy repaid the ineligible expenses in March.

Liberal Leader Justin Trudeau used his time in question period Wednesday -- much as he did the day before -- to question the timeline of Harper鈥檚 knowledge of Wright鈥檚 payment to Duffy.

鈥淵esterday the prime minister said that he did not learn about his chief of staff鈥檚 $90,000 payment to Mike Duffy until Wed. May 15,鈥� Trudeau said. 鈥淵et, media contacted his office on the afternoon of Tuesday the 14th to comment on the payment. His office and Mike Duffy then released identical statements on the source of that payment. How does the prime minister reconcile his assertion that he did not know about the scandal until Wednesday if his office responded the afternoon before?鈥�

Harper said he was only informed 鈥渙f this particular matter on the morning of May 15, that is why I did not know that on the afternoon of May 14.鈥�

Until May 15, Harper said, 鈥渋t was my understanding, this caucus鈥檚 understanding, this government鈥檚 understanding that Mr. Duffy had repaid his expenses using his own resources.鈥�

Harper maintained that stance on Thursday when asked about the scandal by reporters during a joint press conference with visiting Chilean President Sebastian Pinera. Harper also deflected questions about what, if any, instructions he gave to staff to deal with the unfolding crisis.

Liberals lead in support

The poll also looked into support for the federal political parties and found that, if an election were held tomorrow:

  • 36 per cent of decided voters would vote for the Liberals, up percentage one point from last month.
  • 30 per cent would vote for the Conservatives, down two points.
  • 27 per cent would vote NDP, up two points.
  • 4 per cent would vote for the Bloc, down one point, while 4 per cent would vote for the Green Party, up one point.

Nearly four in 10 respondents said they either 鈥渟trongly鈥� or 鈥渟omewhat鈥� approve of the Conservative government鈥檚 performance, down four points from last month, while six in 10 either 鈥渟trongly鈥� or 鈥渟omewhat鈥� disapprove of the government鈥檚 performance.

The poll found that 31 per cent of respondents believe that the Harper government 鈥渉as done a good job and deserves re-election,鈥� down from 42 per cent in December 2010. About 69 per cent said it is 鈥渢ime for another federal party to take over,鈥� up from 58 per cent.

On leadership attributes:

  • 38 per cent would describe Justin Trudeau as 鈥渟omeone you can trust,鈥� down four percentage points, compared to 32 per cent for Stephen Harper, unchanged, and 30 per cent for NDP Leader Thomas Mulcair, up four points.
  • 38 per cent said Trudeau 鈥渉as what it takes to lead Canada,鈥� down two points, while 36 per cent said that of Harper, down one point, and 27 per cent said that of Mulcair, up four points.
  • 38 per cent said Trudeau is 鈥渟omeone who will provide open, responsible and ethical government, down four points, while 33 per cent said that of Mulcair, up five points, and 29 per cent for Harper, down one point.