Help Identifying Flag

Good day,

I am trying to identify a specific flag (I have tried the "flag detective" website with no success).

Here's a description of the flag:

It is a red St. George's Cross on a white background. Centred in the top left square (nearest the flagpole) is a French fleur de lis. In the lower left is a Scottish thistle. In the top right is a red rose (English symbol). In the lower right is an Irish shamrock.

This may be a current or historic flag of a former British colony or member of the British Commonwealth of Nations ... or it may be a regional flag of such a colony or Commonwealth nation. It has been donated to the British Pavilion at the Gathering of Nations festival here in Manitoba, Canada ... but the donor cannot identify it other than as a "British flag".

Any help you can provide would be appreciated.

Sincerely,

Ian
Winnipeg, Manitoba, CANADA