Exchange Rate: CAN:GBP = 2.15194:1.0000 @ 2005-08-29
Overview of Montreal, Quebec, Toronto, Boston, New York:
Zoom Air fly Gatwick/Stansted/Manchester/Glasgow -> Canada on a weekly schedule (not every day), however their fares are in the region of 250 GBP return from UK -> Canada . Flying Glasgow -> Halifax gets the actual flight down to 6h05.
The trouble with flying to Halifax is that this is another hour by air (and about $100 Cdn) to Montreal. Better to go straight to Montreal from the UK/Europe.
VIA Rail have a "Corridorpass" allowing travel between Southern Ontario/Quebec---eg. most of the inhabited parts of Canada and the places with Airports for CAN$254 = 119GBP.
Believe it or not, there are people (and even airports!) across the whole of Canada...
For those able/willing to change in the USA without being arrested, bouncing through New York and taking the train/plane up to Montreal may work. London->New York has the highest competition of any airline in the world and a return is 200GBP or thereabouts if you can work out who has an offer on this week. The trains are 68 and 69 from NYC to Montreal, which takes about 10hours.
British Airways have return flights including taxes for 299.00 GBP Heathrow->Montreal or Toronto, but from the 1st of Novemember so they'll probably be slightly more. 239.00 GBP is the list price for London->New York.
Virgin also compete on the London->East Coast sector but these are still published fares.
Canadian Affair are a block-booker/consolidator with one-ways "from 89.00 GBP" from various airports around the UK.
Agent cheat-sheet for Air-Canada pricing.
Another bucket seller; possibly good for last-minute sales in the 250.00 GBP range.
Used by various linuxy people---they tend to cut their travel-agent's margins/commission-shares very slim. Schipol/CDG->foo will work out cheaper, even changing through Heathrow.
London -> Edinburgh: 720km
New York City -> Montreal: 610km
Boston -> Montreal: 520km
This American sub-continent really turns out to be quite small and disappointing...
Bouncing through their hub in Reykjavik might be possible.
Globalspan seem to be the front/seller for Air Transat who appear to be semi-charterish. 109.00 single from Birmingham->Toronto seems to be the best out of them, but only on Oct 25th and Oct 29th. (Same price for Exeter->Toronto). I'd buy off them just because their web-interface *doesn't* suck!.
Conquest appear to be a front for Zoom.
Really useful mouse-over diagram of European airports and which airlines fly which routes: