Delegates on the annual Speaker's Tour have left on a two-week, $158,000 business-class trip to Europe to learn about the challenges facing the global economy.
Speaker Lockwood Smith, his wife, and four MPs - National's Melissa Lee, Labour junior whip Darien Fenton, Gareth Hughes from the Green Party and New Zealand First's Denis O'Rourke - will tour Britain, Croatia and Brussels for 14 days.
Parliamentary Relations says the estimated budget is $158,000, of which $110,000 will be spent on airfares.
Some of the costs will be met by host Parliaments.
Daniel Tasker from Parliamentary Relations said Dr Smith's wife was going in a "representational" role and the cost of her participation was coming from parliamentary funds.
His colleague Averil Taylor said the Speaker's Tour was an integral part of inter-parliamentary relations and "invaluable to experience sharing".
Staff in the offices of Ms Fenton and Ms Lee said they couldn't comment on the trip's costs but a Green Party spokesman said it would allow MPs to stay in touch with what was happening in other democracies.