There were more than a few raised eyebrows on the train from Ngauranga to Wellington today as 40 young people did the morning commute in their underwear.



They were part of a youth environmental group called Generation Zero, which fights for climate change action and intergenerational justice.



Group organiser James Young-Drew, 22, said the stunt was designed to launch their 50:50 campaign, which is protesting the government's plans to spend $14 billion on highway projects over next decade but not nearly as much on ''smart transport options'' such as light rail, buses and cycleways.



"We were aiming to expose the government's unbalanced transport budget and what better way to do that than by exposing ourselves," he said.



"A lot of people on the train were dumbfounded at first, until they realised what our cause was...quite a few tried to pretend like there wasn't anything out of the ordinary going on."



"But Wellingtonians have a pretty good sense of humour. Most people saw the funny side."



With little more than a woolly hat, scarf and some cotton sheltering them from the elements, the group handed out flyers and talked to people about their cause for an hour at Wellington Railway Station after getting off the train.



Law student Madeleine Foreman, 19, said there were a few nerves when she woke up this morning but those quickly melted away when she and the rest of the group were all standing on the train in their unmentionables.



"It was actually pretty thrilling. You should try it sometime."



An hour standing around in the cold was worth it to make sure her future was being looked after, she said.