The motion carried 53-50 and the matter will be now sent to committee.
"This is a difficult day and it's a difficult proceeding," Bentley said minutes after the vote had taken place. "I make no bones about that."
The motion was triggered by the minority government's refusal to release documents on the cost of cancelling two power plants in Oakville and Mississauga, which the Liberals claim was $230 million.
Prior to the vote, Premier Dalton McGuinty said past governments of all stripes cancelled projects that cost taxpayers' money in the process, but no one was ever charged with contempt.
"This is without precedent in 220 years of parliamentary history," McGuinty said Tuesday, referring to the contempt motion targeting the energy minister.
"I say to my honourable colleagues that while it is within their rights to [move a contempt motion], no other parliament has chosen to do so because it is fundamentally wrong."
The committee will now probe the contempt case then report back to the legislature. It would be at that point that MPPs would decide whether to find Bentley in contempt.
Leaders deflect to committee
Following the vote, Progressive Conservative Leader Tim Hudak said opposition members did not look forward to this moment.
"It’s a sad day in the legislature, it shouldn’t have come to this, but they made the choices, now they have to live with it," Hudak said.
But Hudak wouldn’t say if it was possible for the committee to avoid finding Bentley guilty of contempt.
"This is all up to committee members, but clearly somebody has to be held to account," he said.
New Democrat Leader Andrea Horwath said it is now up to the committee to do its job, but she said that it wasn’t predetermined how the committee will handle the contempt case.
"At this point, all we’ve done is said: 'We have an issue here. The committee needs to look at it to determine whether or not there is contempt and whether or not there is any remedy that needs to be put in place,'" Horwath told reporters.
The NDP leader also suggested that the premier's defence of the minister in the legislature on Tuesday may indicate he is concerend about where the committee will take its investigation.
"It seems to me that the premier is pretty worried about what’s going to be uncovered by the committee."