Irvine Laidlaw, a Scottish industrialist, has lent Mr Hague an 11-seater Falcon jet for the trip - a donation estimated to be worth pounds 70,000.
Labour ministers used the gift to attack the Tories, who have spent weeks hounding them over their use of private jets and Concorde.
David Willetts, the Tory education spokesman, insisted that the loan of a jet was above board and would be declared in the Commons Register of Members' Interests.
"What he [Mr Hague] has done is arrange a very packed tour," he told BBC1's On the Record programme. "He's not turning to the taxpayers in any way to finance it. If you can find some source of private finance... provided it's properly declared, I don't think there's a problem."
Mr Hague is going to Canada and the United States to examine tactics he might use to attack Tony Blair's "third way". He will visit Toronto as part of a five-day tour to hear how Canadian Conservatives made a comeback after an election disaster. One Canadian Tory leader said they had started the fightback by consulting local people and bypassing their own Conservative "elite".
At home, Mr Hague is surrounded by the "elite" from the defeated Tory government. A former minister, Philip Oppenheim, who runs a Cuban bar near Waterloo station, London, said that despite Mr Hague's speech championing a "British way", the Tories were still "arrogant and out of touch".
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