One Direction's Harry Styles and Liam Payne pose in new shoot as they launch ...

By Jennifer Ruby

PUBLISHED: 14:33 EST, 8 July 2013 | UPDATED: 15:15 EST, 8 July 2013

As members of the biggest pop group on the planet they have a manic schedule.

But One Direction's Harry Styles and Liam Payne proved that they still have time to do their bit for those in need, launching their new campaign for youth cancer charity Trekstock on Monday.

Showing their mischievous sides, the boys posed for a new photoshoot to promote the fundraising platform larking around together in their usual fun-loving way.

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Despite being in the middle of their world tour and working on new material for the next album, Harry and Liam took time out to launch the new Prizeo campaign in a bid to raise money for young people suffering from cancer.

Harry, 19, wore a vintage-style Rolling Stones T-shirt for the shoot, while bandmate Liam sported a white top adorned with blue stars.

And displaying their usual on-stage chemistry, the former X Factor stars joked around with each other, while showing off their Trekstock badges.

The pair can also be seen in a series of behind-the-scenes snaps, showing them getting involved with the campaign as they gear up for the photoshoot.

On Monday Harry wrote on Twitter, 'If you fancy it, you can come and hang out with Liam and I for @trekstock?'

The boys were in Montreal last week as they continued their Take Me Home tour, mobbed by fans as they arrived at their hotel.

Keeping their hoards of admirers sweet, the band donned matching national ice hockey team jerseys as they performed on stage on Thursday.

At the end of the night, the band agreed that Montreal was the loudest crowd they'd met on this tour so far

As part of the fundraising campaign, the boys will jet one lucky participating fan over to London from anywhere in the world to have a night out with them.