Independent Mount Gambier MP Troy Bell has confirmed he will lodge an appeal against the 25 guilty verdicts handed down by a District Court jury last week.
The 51-year-old former teacher was found guilty of 20 counts of theft and five counts of dishonest dealing with documents last Thursday.
After meeting with his legal team on Tuesday, the South Australian state MP said "the appeal will be filed".
"I can't talk about the actual appeal but we will definitely be appealing and moving forward," he said.
He said he was in "a very difficult position" because he "can't talk about aspects of the case going forward".
In a statement, South Australian Leader of Government Business Tom Koutsantonis said the state government had sought advice about the guilty verdicts.
He said that if Bell did not lodge a notice of appeal within 21 days of the verdicts, the government would "support a motion to vacate the seat of Mount Gambier, prompting a by-election".
In response to the statement, Bell said he understood parliament had a role to undertake.
"I respect parliament — moving forward I'm always very mindful that these are public positions," he said.
"I have a role to do, as does every MP."
Bell declined to comment about how the verdict had affected him on a personal level.
Bell first won the seat of Mount Gambier, in SA's south-east, as a Liberal candidate at the 2014 state election, after working as a public servant for the Department for Education.
He quit the Liberals after he was charged in August 2017 and retained the seat at the 2018 and 2022 state elections as an independent.
During the three-month criminal trial which began in June, seven years after he was charged, the jury heard Bell failed to return $436,023.24.
Prosecutor Jemma Litster said that figure was a "conservative calculation" of the amount stolen.
She told the jury the money was transferred into his personal accounts, allowing him to use the money for his own purposes including to pay credit card debts, offset his mortgage and for property investments.
Ms Litster said Bell was able to commit the fraud unnoticed for some time because he had a "charismatic and persuasive" personality, was "well-liked" and "trusted in his professional and social circle".
She told the court he became "particularly" financially ambitious in mid-2009, when he and his wife purchased their family home in Mount Gambier.
"Bell was moving funds consistently between his loan and personal accounts to settle debts," she said.
"It's the prosecution case that all of the financial circumstances in the lead-up to to the allegations are relevant to explain why the theft may have occurred."
Bell denied the allegations, which his legal team described as a "mad rabble".
In his closing submissions to the jury, Bell's defence barrister Nick Healy said the case against his client was "all sizzle and no sausage".
"The entire prosecution case is misguided, it is misleading, it is confused and confusing and it is internally inconsistent," he said.
He is next scheduled to return to court next month.