With air fares to Canada sky-high, can you save by travelling there via the USA?

Q. Flights to Canada seem so expensive! Any tips for getting there with enough cash to buy a hot dog on arrival? Should I go via the US and onwards by bus? Lynne Pointer, Oxfordshire

A. Going east to west, the main gateways to Canada are Montreal, Toronto (pictured) and Vancouver. They roughly correspond, in terms of flying time from the UK, to Boston, New York and Seattle. From each of those cities you can reasonably travel overland north of the border into Canada.

Yet the fares vary dramatically. We have checked fares for non-stop scheduled flights from Heathrow, travelling next May. For the big eastern cities, New York and Boston are far cheaper than Toronto and Montreal.

The US cities are available for about £435 return on quality airlines, while their Canadian counterparts are coming in at £675. The difference in fare would certainly make it worth putting up with a 10-hour bus journey from New York or Boston. You could also build in an extra stay in either of these fine cities.

But before you book, bear in mind that you will be required to pay $14 (£9) for an "Esta" to gain admission to the US. In addition, Air Canada and British Airways are not the only game in town. Air Transat, bookable through Canadian Affair, has excellent fares from Gatwick and other UK airports. In May, its Gatwick-Toronto fare is about the same as the prevailing New York and Boston prices.

If your destination is Vancouver, the tables are turned. Because BA competes with Air Canada from Heathrow to the British Columbia city, you can expect keener fares than to Seattle – where BA has a monopoly. In May, the fare to Seattle is around £800 return, with Vancouver available for around £25 less. Yet you need not pay anything like those prices, if you are prepared to change planes along the way. To Seattle, a quick connection at Minneapolis on Delta brings the fare down to around £575. Vancouver is available via Amsterdam on KLM for around £600.

Finally, if Montreal happens to be your final goal – don't buy a hot dog. Head for Schwartz's Hebrew Delicatessen and indulge in a medium fat smoked beef sandwich, which will transcend the finest American hot dog.