All eyes are squarely on former Gov. Bob McDonnell.

He took the stand in his defense Wednesday in the Virginia trial of the century.

Mr. McDonnell, 60, is the first governor to be criminally indicted in the Commonwealth’s 226-year history. His wife, Maureen, also is charged.

The ex-governor and his defense team quickly went to work to shoot holes in prosecutors’ claims that Mr. McDonnell participated in a secret gifts-for-political favors scheme while in office.

His main aim on the stand is to discredit the prosecution’s attempt to prove that he gave former Star Scientific CEO Jonnie Williams official help to promote the dietary supplement Anatabloc in exchange for receiving loans and luxury gifts for himself and his wife.

“I would say my administration did very little other than provide the routine access to government that any donor or non-donor, any gift-giver or non-gift-giver, would be able to get,” Mr. McDonnell testified.

The former governor said he envisioned Anatabloc might provide much-needed jobs when Mr. Williams first pitched it to him aboard Mr. Williams’ private jet in 2010.

“Anything we could do to help that part of the state I thought would be a really good thing,” Mr. McDonnell said.

The ex-governor was asked earlier about the lures of money and politics.

“You gotta know where the lines are,” Mr. McDonnell said.

He said he considered it a fundamental part of his job to allow access to everyone, even if he could not do it in person.

“My rule of thumb is every contributor wants something,” Mr. McDonnell told the jury. “For many, it’s good government, clean government.”

Mr. McDonnell was to continue his testimony Thursday.

Earlier in the day, Alan Kosowsky, a certified public accountant, testified that the McDonnells had more than $170,000 in available credit on their credit cards in 2011 when they got their first $50,000 loan from Mr. Williams.

Mr. McDonnell’s sister, also named Maureen like Mrs. McDonnell, testified Tuesday that she was financially solvent and had plenty of money at the time Mr. McDonnell accepted a $50,000 loan from Mr. Williams for two struggling beachfront properties she and her brother co-owned.

She said she approached her brother about buying the properties after her accountant advised her to purchase them to broaden her portfolio.

She said she preferred her brother accept a loan from Mr. Williams rather than have her pay off the property debt with a credit card because she did not want to risk damaging her credit.