An Independent MLA who filed a complaint with the RCMP about the United Conservative Party leadership race says his former party has sent him a cease and desist letter.

Prab Gill has accused UCP Leader Jason Kenney's campaign team of tinkering with the voting system to favour the eventual winner during the 2017 leadership contest.

Gill has asked both the RCMP and Alberta's elections commissioner to investigate the race, which Kenney won handily over two other contestants.

"Kenney and UCP sent me a cease and desist order," Gill said during an interview with CBC News. "They [the UCP] want to use the court system to shut down a whistleblower."

Gill said the letter, dated Feb. 25, was sent to him by lawyer Steven Dollansky on behalf of Kenney and the UCP.

In the letter, Dollansky writes that Gill's allegations are "plainly false and defamatory."

Dollansky adds the statements Gill made in his complaint to the RCMP "have caused significant damage to our clients' reputations and will continue to cause damage until a retraction and apology is issued."

The letter demands Gill stop making further comments about his complaint to the RCMP, and issue a written retraction and apology to Kenney, the UCP, and other people mentioned in the context of his complaint.

The letter warns of a potential defamation lawsuit against Gill if the apology and retraction are not issued.

Kenney reiterated the threat at a news conference Wednesday afternoon in Edmonton, saying he is "absolutely certain" Gill's allegations are "baseless."

"What we're saying here is if he does not stop this campaign of defamation, which apparently is now being co-ordinated with the premier's office, that we would be happy to see him in court under oath," Kenney said.

Kenney said his co-ordination comment referred to an apparent meeting this week between Gill and a senior NDP staff member.

Through a heavily edited video captured by three UCP staff members, the comings and goings from Gill's MLA office were recorded and posted on social media.

Video posted

Independent MLA Prab Gill says he is being bullied and intimidated by the UCP (CBC)

The video was posted to Twitter on Tuesday by Unite Alberta, the official Twitter account for Kenney's office.

The black-and-white, slow-motion video shows Jeremy Nolais — director of issues management in the office of Premier Rachel Notley — walking out of Gill's MLA office in the Federal Building. It shows Gill emerging later from the same office.

The silent video is 51 seconds long and contains captions, along with a message raising the question of whether Gill intends to join the NDP.

Gill, who has said he will not seek re-election this spring, called the video "creepy" and said it was an attempt to intimidate an MLA who was doing his job.

The meeting with Nolais, said Gill, was about funding for a high school in his riding.

"Three UCP staff members camping outside on taxpayers dime, trying to videotape who comes and who goes outside my office — this is crazy," said Gill, who expressed concern that what he called "Trump-style politics" are being used in Alberta.

UCP defends letter and video

The UCP said there was nothing strange about the video, and characterized the meeting between Nolais and Gill as "not normal."

"This is in a common area in the building, it's not a normal thing to see a senior adviser to the premier of Alberta leaving an independent MLA's office in the Federal Building," said UCP house leader Jason Nixon.

"Someone who was standing there found it interesting and took a tape of it."

Nixon said the NDP government does similar things "all the time" and added that MLAs are aware they could be videotaped at any moment.

Gill, the MLA for Calgary-Greenway resigned from the UCP caucus in July amid allegations of ballot stuffing following a June 30 constituency association meeting.

Kenney has strenuously denounced Gill's accusations, calling him a "discredited politician."