Wildrose Leader Danielle Smith, in a statement Monday, said the payments have to go beyond political staff to include all senior managers and government officials.
"The problem runs much deeper,” said Smith.
"Albertans are ready to send a message that they’ve had enough of government insiders getting rich off of them, and they’re ready to vote for a party that will put their interests first."
The Wildrose said a freedom-of-information search has revealed that cabinet minister Manmeet Bhullar's office paid out $5.7 million to senior staff when he ran the Service Alberta department.
Bhullar is now infrastructure minister.
But a spokeswoman for Prentice disputed the Wildrose number, saying the $5.7 million represented not a payment, but an estimated liability for severances.
"In the end, only $1.8 million of this amount was paid to severed employees between 2011 and 2014," Emily Woods said in a statement.
Woods also said that "Beginning in January 2010, Service Alberta has achieved staff reductions, mostly through attrition, that will save Albertans an estimated $21 million every year."
Prentice promised to reform the severance system after former premier Alison Redford's inner circle left with more than $1 million in severance earlier this year.
The government has also been criticized for hefty payouts for executives with Alberta Health Services, which handles front-line care.
Smith said the Wildrose, if elected, would pass a bill limiting severance packages for all senior officials and political staff to no more than $100,000 for five or fewer years of employment.
It would be no more than $200,000 for more than five years on the job.
The party would also outlaw collecting two severances within a five-year period, and make all severance agreements open to public scrutiny, she said.