QUEBEC -- Calling her behaviour "highly reprehensible" and part of a "culture of deceit," a judge sentenced former Quebec lieutenant-governor Lise Thibault to 18 months in prison on Wednesday.

The sentence was handed down six years after Thibault, now 76, was charged with fraud and breach of trust.

The Queen's former representative left the courtroom in handcuffs in her wheelchair and was then incarcerated.

How long that lasts remains to be seen because Thibault's lawyer, Marc Labelle, immediately signalled he would seek leave to appeal the sentence and try to have her released from jail pending those proceedings.

Thibault was charged two years after a 2007 report by the federal and provincial auditors general revealed she claimed more than $700,000 in improper expenses when she held the vice-regal post between 1997 and 2007.

Her trial heard the money was spent on gifts, trips, parties, meals and skiing and golf lessons.

Quebec court Judge Carol St-Cyr also ordered Thibault to reimburse $200,000 to Ottawa and $100,000 to Quebec.

He highlighted Thibault's "culture of deceit" and her mitigated remorse as he handed down the sentence in a jam-packed courtroom.

"It is important that the public know this behaviour was highly reprehensible," he said.

"A sentence in the community would not satisfy the legal requirements...to maintain the confidence of citizens with regard to public institutions."

Labelle, who had been seeking a sentence to be served in the community, called St-Cyr's ruling "severe."

"Jail is supposed to be the last resort -- that's what the law says," he said. "So we're saying she should have been given that chance and not be incarcerated."

He also expressed concerns about her health, saying she is taking medication and has what he called a "severe condition."

Crown prosecutor Marcel Guimont expressed satisfaction with the sentence, even if it was shorter than the four years he had asked for.

"It's a prison term and I think this case deserved a prison term," he said.

Besides the four-year sentence, the Crown was seeking the reimbursement of $430,000.

Labelle said last May the maximum Thibault should pay back is $372,000 and that $272,000 should come from money left in her foundation, which helps the disabled.

Thibault originally pleaded not guilty but switched pleas last December because, according to Labelle, she came to a better understanding of the evidence and the law.

She testified at the trial she had little to show financially for her time as vice-regal -- that a divorce ate into her savings and that she lived on a $30,000 pension.

St-Cyr also ruled against a pair of motions filed by Labelle, who argued the case should be dismissed because the accused benefited from royal immunity.

Labelle said that meant Thibault was not a civil servant and therefore could not face criminal charges.

The judge said that, according to constitutional law, the lieutenant-governor does not enjoy the same benefits as the Queen.

St-Cyr also noted that under the Constitution, the lieutenant-governor is a civil servant, adding such an affirmation is even posted on the lieutenant-governor's website.

Thibault burst into tears last May when St-Cyr asked her whether she had anything to say following the Crown's recommendation she receive the four-year prison sentence.

"I never thought for one second I'd be standing before you," an emotional Thibault told the judge.

"Since my youth, I've always helped everyone...I can't imagine that my grandchildren will have a memory of their grandmother being treated like a thief."