Don MacIntyre has officially resigned as a member of Alberta's legislative assembly.

On Friday, United Conservative Party (UCP) Leader Jason Kenney issued a statement that MacIntyre, the MLA for Innisfail-Sylvan Lake, had resigned from caucus.

Details surrounding the circumstances leading to MacIntyre's departure have not been made public.

Last week, MacIntyre posted on Twitter that he was leaving politics to focus on his family. Only a few days earlier, MacIntyre was in his seat in the legislature as leader Jason Kenney was sworn is as a new MLA.

A byelection must now be called within the next six months to fill the vacant seat.

MacIntyre was elected in 2015 with the Wildrose party, and emerged as an outspoken critic on issues such electricity power purchase agreements.

Prior to that, he was a part-time instructor in the alternative energy program at NAIT, and worked as the chief technical officer for a private overseas geothermal company.

MacIntyre was criticized by the NDP last year after he suggested that science hasn't conclusively proven that climate change is a man-made problem.

The news of MacIntyre's sudden exit Friday came the same day as Kenney announced that MLA Derek Fildebrandt would not be allowed to rejoin the UCP caucus, after he pleaded guilty to illegally shooting a deer on private land.

Fildebrandt remains as the Independent member for Strathmore-Brooks.