One Direction
The four remaining members of One Direction Jason Merritt/Getty Images

After calling on millions of 'Directioners' to join their call for action on "extreme poverty, inequality and climate change", One Direction have received the support of an unlikely fan - Hilary Clinton.

Earlier in July Harry Styles, Louis Tomlinson, Niall Horan and Liam Payne teamed up with charity action2015 in a bid to pressure world leaders into exerting their influence ahead of the United Nation's climate change summit in Paris this September.

In a video posted on Twitter, the X Factor stars urged fans to share videos and pictures that reflect issues that are important to them.

"Time and time again, you've shown us how incredible, passionate and creative you all are, and now we want to ask you to come together with us and use that to make a change for good," the lads said.

"Please will you join us to put pressure on our leaders. All you need to do is tell us what you want your world to look like in the future. You can make videos or send us pics, it's easy. Become part of Action/1D, make your voice heard and make 2015 the year we change our futures forever."

Clinton backed the British boyband's new #action1D campaign, tweeting that the "the boys are right."

The Democratic presidential candidate's endorsement comes days after Styles said that the foursome has gone from strength to strength since Malik's exit, going so far to say that their shows without him have been some of the best they have ever done.

Bradford-born Malik announced he was leaving the group after five years on 25 March, claiming he wanted to be a "normal 22-year-old".

"There have been incredible shows across Europe... some of the best we've had," Styles told Entertainment Weekly.

"The only changes have been that the parts Zayn sang have been picked up by different people. Other than that, the shows have been going absolutely great."

He added that Malik's role in the group has since been filled by Payne, who "stepped up" to do the big solo during their performances of The Story Of My Life.

"Liam stepped up to do the high notes. He kicks them in the b******s every show. He doesn't hold back."