if u have the PR of Canada, despite to any nationality, NO NEED OF TRANSIT VISA..!!
Enjoy ur stay in LONDON..!!
correct, no transit visa needed for uk if u have prr for canada, check uk border agency website
http://www.ukba.homeoffice.gov.uk/travellingtotheuk/transitthroughtheuk/transitdocuments/exempt/This page explains who is exempt from needing a direct airside transit visa (DATV) when passing through the UK. You may need another type of visa, however, and should see Direct airside transit visa and visitor in transit visa for more information.
Regardless of your nationality, you may be exempt from the requirement to hold a direct airside transit visa when passing through the UK.
You are not required to hold a transit visa if you hold, or the person with whom you have arrived in the UK holds on your behalf:
■a valid visa for entry to Australia, Canada, New Zealand or the United States of America and a valid airline ticket for travel through the UK as part of a journey from another country or territory to the country for which the visa is held;
■a valid visa for entry to Australia, Canada, New Zealand or the United States of America and a valid airline ticket for travel through the UK as part of a journey from the country for which the visa is held to another country or territory;
■a valid airline ticket for travel through the UK as part of a journey from Australia, Canada, New Zealand or the United States of America to another country or territory, provided that you do not seek to transit the UK on a date more than six months from the date on which you last entered Australia, Canada, New Zealand or the United States of America with a valid visa for entry to that country;
■a valid USA I-551 Permanent Resident Card issued on or after 21 April 1998;
■a valid Canadian Permanent Resident Card issued on or after 28 June 2002;
■a valid common format Category D visa for entry to a European Economic Area (EEA) state;
■a valid common format residence permit issued by an EEA state under Council Regulation (EC) No. 1030/2002;
■a diplomatic or service passport issued by the People's Republic of China;
■a diplomatic or official passport issued by India; or
■a diplomatic or official passport issued by Vietnam.