"The government, the caucus, the cabinet, and the party are in a real important phase of renewal," Hughes said in an interview Thursday. "I want to contribute to that renewal.
"I think it's important that we take every opportunity to refresh all of those institutions in Alberta — and this is how I can contribute to that in support of Jim Prentice."
Hughes, a longtime confidante of Prentice, said he would stay on as the member of the legislature for Calgary-West until the spring 2016 election.
But he added he would consider stepping down if Prentice wanted to run for that particular seat in a byelection.
Hughes has served in both provincial and federal politics.
He was the Progressive Conservative MP for Macleod from 1988 to 1993. Years later and prior to running for office provincially, he headed Alberta Health Services, responsible for the province's front-line care.
Elected as an MLA in 2012, Hughes served as energy minister and in the municipal affairs portfolio under former premier Alison Redford. He led the restructuring of Alberta's disaster recovery program following the catastrophic floods of 2013.
In Energy, he shepherded the creation of a single energy regulator and, last October, in China he signed a deal to increase trade ties and collaboration.
"That was a real highlight for a kid from Longview."
He ran briefly for the PC party leadership this spring after Redford resigned, but withdrew his candidacy soon after to support Prentice.
He said he told Prentice earlier this summer that he was thinking about not running again and confirmed that to him this week.
The decision to leave was partly based on helping Prentice, Hughes, said, but he added it was also a personal call he made while travelling with his wife and children this summer.
"There are other aspects to life," he said, noting that he turned 60 this year.
He will keep busy post-politics looking after his business interests, he said.
Prentice is mulling options for a new cabinet he has promised will be announced when he is sworn in next week. A date has not been set.
Prentice won the leadership contest last weekend on a platform of cleaning up the spending and entitlement scandals discovered during Redford's time as premier.
Prentice, a former Calgary MP and Conservative cabinet minister, still needs to win a seat in a byelection to sit in the legislature.
Hughes said his decision to leave should not be viewed as a call for others to quit in the name of renewal.
Everyone needs to do what they can, he said.
"Everybody has to make their own decisions."
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