An assault charge against the head of Calgary's police union has been dropped, his lawyer confirms.

Sgt. Les Kaminski had been charged with assault with a weapon and perjury in connection to a traffic stop in downtown Calgary in 2008 that ended in the arrest and trial of Jason Arkinstall.

Kaminski's lawyer, Alain Hepner, told CBC News the assault charge was withdrawn Monday morning.

"He was delighted that the assault charges were withdrawn, and we move forward to the next phase, which is the trial on the other allegation," said Hepner.

﻿Kaminski﻿ still faces a perjury charge.

"Les is a 31-year veteran of the Calgary Police Service who's been on the street for years. He's put himself in harm's way numerous times," Hepner said.

Hepner expects the Court of Queen's Bench trial will be held in the fall or early winter.

Arkisntall, himself, was charged with uttering threats against Const. Brant Derrick, one of the arresting officers.

A provincial court judge acquitted Arkinstall in 2011, saying in his written decision that Kaminski and Derrick were not credible witnesses.

He was elected as head of the 2,200-member police union last November.