Posted: Sat Jan 19, 2008 2:07 am-
When I spoke to someone at passport canada about this a couple of weeks ago I was told that I would simply have to retain the earlier passport and use two passports for the duration of my stay in Britain.
However I also recall reading something on one of the british authorities sites saying that they no longer allowed this to occur and that if you had a visa it had to be in the current valid passport. I haven't been able to find this information again but admittedly i haven't been looking very hard.