Washington (CNN) - Virginia Gov. Bob McDonnell, once considered a possible 2016 Republican presidential candidate, continues to see his poll numbers decline amid a deepening gifts controversy.
According to a new Quinnipiac University poll released Wednesday morning, McDonnell's approval rating among Virginia voters now stands at 46%, down from 49% in May and 53% in March. And his disapproval rating has jumped from 28% in May to 37% now. The 46% approval rating for McDonnell is an all-time low in Quinnipiac polling, and is down dramatically from his all-time high of 62% back in October 2011.
McDonnell, who was under consideration last year as a potential running mate to GOP presidential nominee Mitt Romney - and who many considered would make his own run for the White House in 2016 - has been under investigation by the FBI for his relationship with a certain donor who provided multiple gifts, including large financial contributions, to the governor and his family.
The latest allegations, reported by the Washington Post last week, revealed the donor, Jonnie Williams Sr., had given $70,000 to a corporation owned by McDonnell and his sister, and a separate $50,000 check to McDonnell's wife. Williams owns a dietary supplement company that the McDonnells have promoted in recent years.
The FBI has not made any announcements about the investigation, nor has it given any indication that the governor will be charged.
For his part, McDonnell maintains the company has not received special state support, such as state benefits, economic development grants, targeted money from the budget, or board appointments.
By a 41%-30% margin, Virginia voters say they aren't satisfied in the way their governor is handling the controversy surrounding him, with 27% saying they think the wrongdoing is serious, 5% saying it's not serious, 16% saying he's not involved in any wrongdoing and nearly half of those questioned saying they haven't heard enough to make a judgment.
McDonnell sharply tamped down on rumors last week that he may be resigning as part of a plea deal with federal prosecutors.
"I don't know where these things come up. Some of the press accounts have just been completely out of control about rumors, about resignation, so forth," he told CNN affiliate WTVR in an interview that ran last Tuesday.
McDonnell said the scrutiny has been disappointing.
"Thirty-seven years - no one's raised questions about my integrity or my character," he said.
According to the poll, only 16% of Virginia voters say McDonnell should resign, including 4% of Republicans, 29% of Democrats and 13% of independent voters. More than six in ten say the governor should not resign, with nearly one in four unsure.
"The lofty levels of 2-1 job approval that Virginia Gov. Bob McDonnell once enjoyed have slipped away with six months left in his term. He's under 50% for the second poll in a row, with just a 9-point net approval after substantial media coverage of his relationship with a campaign donor and associated problems," said Peter Brown, assistant director of the Quinnipiac University Polling Institute.
"Almost 80% of voters are aware of the controversy and seem to be somewhat concerned. The bottom line seems to be that they view him as just another politician, but at this point they are not clamoring for his scalp," adds Brown.
Virginia law prohibits governors from serving consecutive terms, so McDonnell is not running in this year's gubernatorial election. This year's GOP gubernatorial nominee, Attorney General Ken Cuccinelli, also has connections to Williams which have come under scrutiny.
The Quinnipiac University poll was conducted July 11-15, with 1,030 registered voters in Virginia questioned by telephone. The survey's overall sampling error is plus or minus 3.1 percentage points.