London: The successor to Boris Johnson's seat in Britain's parliament will be chosen in a by-election vote on July 20, the local council said on Thursday, after the former prime minister quit over an investigation into his conduct.

The Conservatives selected Steve Tuckwell to be their candidate for the vote, the party said in a statement on Thursday.

Johnson last week said he would stand down as the lawmaker for Uxbridge and South Ruislip, an area in West London, after he read a parliamentary report over whether he misled parliament over gatherings at his office during COVID lockdowns.

That report, published in full on Thursday, found he had deliberately misled parliament over the rule-breaking parties, though Johnson has dismissed the report as a "lie" and a "charade".

"The by-election for the parliamentary constituency of Uxbridge and South Ruislip will take place on Thursday 20 July 2023 following the resignation of Boris Johnson as a Member of Parliament on Friday 12 June," Hillingdon Council said in a statement.

Johnson stood down as prime minister last year.

Another by-election to replace close Johnson ally Nigel Adams in his seat in North Yorkshire will be held on the same date after he resigned on Saturday.

Conservative lawmaker Nadine Dorries has also said she would stand down in support of Johnson, but has not formally done so and there is no date yet for the by-election to replace her.