Nigel Wright 鈥渨ill not be shying away from any questions鈥 when he takes the stand Wednesday at Sen. Mike Duffy鈥檚 trial, a source close to Stephen Harper鈥檚 former chief of staff tells 麻豆传媒.

The source also said that Wright 鈥渢akes the duty of the (court) process very seriously鈥 and intends to 鈥渄emystify鈥 any lingering questions from the public and the media.

Wright is expected to testify about his secret $90,000 payment of Duffy's allegedly improper living and travel expenses in 2013. Wright wrote Duffy a personal cheque and has said that Harper had no knowledge of the arrangement.

Harper has also denied knowing anything about Wright鈥檚 $90,000 cheque to Duffy.

Court documents quoted Wright as saying in a 2013 email that 鈥渨e鈥檙e good to go from the PM.鈥

But at a campaign event this weekend, Harper said: 鈥淭he words you鈥檙e quoting are not my words. They鈥檙e somebody else鈥檚.鈥

Wright intends to explain to the court what the 鈥済ood to go鈥 comment meant, the source said.

The RCMP laid 31 charges against Duffy. Three of them are related to the $90,000 payment: fraud on the government, bribery and breach of trust.

Harper will be far away from Ottawa this week as Wright takes his turn as the star witness at Duffy鈥檚 trial. The Conservative leader鈥檚 campaign is heading to northern Canada.

Harper repeated on Tuesday that he had told Duffy, a former Conservative senator, that he 鈥渟hould repay his expenses.鈥

鈥淚 was told that he was going to repay those expenses, and we were all told he had repaid those expenses,鈥 Harper said at a rally in Markham, Ont.

With a report from CTV鈥檚 Katie Simpson and files from field producer Philip Ling in Ottawa