Applying Visitor Visa to Visit Canada in London

[Moh28]

Hello,

applicant hold a foreign passport and requires a visa to visit Canada.

applicant is  currently on a 6 month visitor visa in the UK at his son's place

applicant now wants to visit his daughter in Montreal Canada.

Is it possible applicant applies for temporary stay visa ( visitor visa ) at the London Canadian High Commision?

If so, which application form to use? and how long will it take to get the visa and the documents to supply?

Please let me know and shre your experience.

Thanks