[Dion]

But Duffy's effort to recast himself from villain to victim is having an impact.

First, it guarantees the prime minister will be back on his feet again Wednesday, presumably to deny he knew anything about the deal, and to sidestep questions about why he insisted in May that Wright acted alone.

Second, it creates a credibility contest between Harper and Duffy. For the first time, the senator's version of the story is being given a full public airing, and, for the time being at least, he's casting doubts about the government's version of events.

Canadians already knew from RCMP documents that Nigel Wright did not act alone as the prime minister first suggested. At least three other former members of his office were aware of the repayment scheme.

The government's own talking lines — that Wright acted alone — morphed long ago into claims that Harper's former chief of staff accepted sole responsibility.

These are the kinds of shifts in messaging the opposition continues to highlight when challenging the credibility of the government's claims.

Duffy's first public comments on the scandal has given them new ammunition, even if the Conservative-dominated Senate endorses the government's efforts to suspend him and the others without pay.

It's now Duffy's word against the prime minister's. A battle for credibility that only one of them can win.

http://www.cbc.ca/news/politics/sena...-war-1.2159732