Commenting on an investigation that found the minister of national defence racked up nearly $3 million worth of flights aboard federal jets, the minister's parliamentary secretary reiterated on Sunday that Peter MacKay did not break travel rules.

When asked on CTV's Question Period whether MacKay "at no point" contravened the government's guidelines for ministerial travel, Chris Alexander said "the short answer is yes," before adding that members of the Conservative government have "used challenger aircraft three-quarters less" than their predecessors.

"This government has been extremely exacting of its ministers and everyone in government by putting in place the toughest measures for accountability, transparency, making sure we know what assets ministers have and making sure we watch like hawks what their means of travel are," Alexander said.

"Every ounce of evidence shows MacKay and others members of government have followed the rules."

However, Liberal MP and former defence minister John McCallum said that in his view MacKay broke two rules.

"One, you're not supposed to fly in search-and-rescue helicopters because those are very few and they're designed for search-and-rescue and second you're not supposed to fly from a fishing lodge," he said, referring to a CTV News report that MacKay was picked up from a vacation at the Gander River fishing camp by one of only three search-and-rescue helicopters available in Newfoundland.

A CTV News investigation found that the total costs of MacKay's 35 flights aboard the government's Challenger jets since he became defence minister in 2007 amounted to $2,927,738.70.

Documents showed that out of the 35 flights logged by MacKay, only nine were for repatriation ceremonies and many were for press conferences and political announcements.

Cabinet ministers are encouraged to take commercial flights whenever possible.

Prime Minister Stephen Harper defended MacKay's frequent flier miles on Thursday, saying that the frequency of the minister's flights aboard government jets is low compared to his predecessors.

McCallum said that when he was in office there were strict rules that ministers followed when using government jets.

"Ministers could use those jets only when on government business and only when commercial travel was not available," he said.

The NDP's Jack Harris said that the use of these jets is a frivolous waste of taxpayers' money.

"It just shows that the minister, and this government, is out of touch with ordinary people," he said on Sunday.

Alexander disagreed, however, suggesting instead that the nature of the minister's job requires flying on the jets at times.

"A minister of national defence and other ministers have an irreducible minimum number of events they need to be at and they won't always be able to get there commercially," he said.

General Walter Natynczyk, Canada's top soldier, was also criticized for his use of the Challenger jets after it was discovered that his flights cost taxpayers $1 million over the past three years.

On one flight, Natynczyk used a jet to join his family on vacation in St. Maarten.