THE Prime Minister has pulled out of a conference of northern Conservatives despite a key upcoming by-election in the region triggered by the resignation of one of his disgraced MPs.

Boris Johnson cancelled a scheduled appearance at the event in Yorkshire on Friday as Tory activists pound the pavements of Wakefield ahead of the by-election triggered by the resignation of convicted paedophile Imran Ahmad Khan.

He had been due to address members of the Northern Research Group at a conference in Doncaster but instead travelled to Ukraine for a meeting with President Volodymyr Zelenskyy.

The Wakefield by-election may deliver yet more electoral misery for the Tories, following defeats in North Shropshire and Chesham and Amersham.

READ MORE: Boris Johnson travels to Ukraine for second meeting with Zelenskyy

Nadeem Ahmed, defending the seat for the Conservatives, has raised eyebrows for comparing his predecessor with notorious serial killer Harold Shipman.

He told The Telegraph: “Harold Shipman committed suicide in Wakefield prison. He was a GP.

“One of the most, you know, a trusted professional like teachers and others.

“When they put a vaccine in our arm, we trust what they’re putting in us.

“Have we stopped trusting GPs? No and we know that [Shipman] was one bad apple in there.”

Shipman – dubbed Dr Death in the media – is thought to be the most prolific serial killer in modern history, murdering an estimated 250 people.

Khan resigned his seat and was expelled from the Conservative Party after he was found guilty of groping a 15-year-old boy at a party in Staffordshire in 2008. He was sentenced to 18 months in prison.

Wakefield voters will cast their ballots on the same day as those in Tiverton and Honiton, another seat left vacant by Tory scandal.

The former MP Neil Parish was outed as having watched pornography twice in the House of Commons.

READ MORE: MP who 'watched porn in the Commons' suffers X-rated name change on Wikipedia

Lancashire MP Jake Berry has previously described the conference as a fantastic chance to discuss ideas that will help us Level Up the North” and give members “the opportunity to shape our policy asks from Government”.

Johnson used his visit to Ukraine to pledge training to Zelenskyy’s troops to fend of the Russian invasion.

The war-torn country was recommended for candidate status for EU membership on Friday, subject to conditions.