Senator Mike Duffy took the witness stand for his second day of testimony in an Ottawa courtroom on Wednesday. As the defence tried to establish the embattled senator as a law-abiding citizen who followed the rules of Senate residency and expenses as he understood them, Duffy also testified about the inner workings of Prime Minister鈥檚 Office under Stephen Harper.

The defence also tried to pick apart the Crown鈥檚 theory that Duffy was living beyond his means and thus had financial motive to unlawfully claim expenses.

Duffy has pleaded not guilty to 31 charges of fraud, bribery and breach of trust.

Here are five things we learned from Duffy鈥檚 second day of testimony:

Claiming expenses

Duffy told the court that, shortly after his appointment to the Senate, he was instructed by the deputy chairman of the internal economy committee at the time, Conservative Sen. David Tkachuk, to claim everything he is entitled to, including per diems, even though Duffy said he didn鈥檛 like per diems.

Duffy testified that Tkachuk told him, if he was going to represent P.E.I. as a senator, he had to make the same expense claims any other senator from P.E.I. would make.

Duffy described Tkachuk as a 鈥済uru鈥� for new senators who had questions about the Upper Chamber.

Travel

Duffy says he was also told that, when he was travelling across the country for partisan events, he was on public business, and that senators were always on public duty. In filing travel forms, Duffy said, he was told to note both senate and public business, and he was to keep notes about his travels. On the stand, Duffy testified repeatedly that he and other high-profile Canadians were recruited to help win over voters.

Shortly after becoming senator, Duffy said he was told the Senate would pay for a trip back to P.E.I. after an orientation meeting. Asked if it was his idea to expense the trip, Duffy replied, 鈥渘ot at all.鈥�

Hours into his testimony on Wednesday, Duffy was asked about charges related to travelling for funerals, prompting the senator to say, 鈥淚 am so fed up with this.鈥� Duffy repeated that he was on Parliamentary business, and that senators were encouraged to travel.

Inside the PMO

During his testimony, Duffy described his dealings with the Prime Minister鈥檚 Office under the Harper government, explaining that his communications with the PM were expected to go through Ray Novak. Duffy said Harper would read emails, but he never wrote on his laptop. Instead, Novak did the writing.

He said Harper would write on yellow Post-It notes and place them on documents rather than mark the documents themselves. That way, there were 鈥渘o fingerprints,鈥� Duffy said. If Harper was never asked anything, and was never told anything, he had deniability, Duffy said.

Alleged slush fund, financial motive

When asked about an alleged $65,000 slush fund that the Crown argued Duffy used to pay for things such as a personal trainer and makeup artist, the senator vehemently denied ever breaking the rules, let alone the law, and said he never received 鈥渁 penny鈥� from anyone, ever.

Duffy said all his claims were done openly, honestly and in good faith. He said everyone in authority, including Harper, told him he was within the Senate rules, but that the rules are inexplicable to the Conservative base.

Duffy鈥檚 defence also tried to quash the Crown theory that Duffy was in need of money, which was a reason for him to defraud the Senate. The defence presented non-taxable inheritances Duffy and his wife had received, showing they were not in need of money.

P.E.I. property

Court also heard details about Duffy鈥檚 renovations at his property in Cavendish, P.E.I., including the costs of construction, energy audits, and roofing.

The defence tried to establish that the renovations were done because Duffy intended to make the house his permanent residence. Duffy said that the total cost of the renovations 鈥� paid for by him and his wife 鈥� was just under $100,000.

With files from CTV鈥檚 Katie Simpson and field producer Philip Ling