Updated June 12, 2017 22:59:05

One of the most powerful women in the world and the former prime minister of New Zealand, Helen Clark, says the United Nations needs to shake-up its electoral process.

Ms Clark, listed by Forbes as the 22nd most powerful woman in the world, served as head of the UN Development Programme up until earlier this year and last year she ran for the role of UN secretary-general.

Her campaign for secretary-general is documented in the film, My Year With Helen, which premiered at the Sydney Film Festival at the weekend.

It tells the story of how a girl from a remote New Zealand farm grew up to become prime minister and attempted to break one of the final glass ceilings, in her bid to be the first female secretary-general.

Ms Clark told Lateline that radical change was needed at the UN because the Security Council holds all the power when it comes to appointing the secretary-general.

"The Security Council has taken on itself, in effect, the election of the secretary-general. So when they make a decision it goes to the General Assembly as a fait accompli," she said.

"The radical thing to do, the sensible thing to do would be to say the member states as a whole should choose the secretary-general and let them do exhaustive balloting to work their way through the single candidate.

"But at the moment it's like an executive is deciding and within that executive of 15 there are five permanent members and they have a disproportionate say because they're carrying a veto over any decision."

Photo: Helen Clark and film director Gaylene Preston. (My Year With Helen: Helen Klisser During)

Ms Clark said there was still a lot of work to be done when it came to achieving equal representation for women.

"I'm constantly shocked by how little progress the whole world has made," she said.

"The number of women leaders in the world actually peaked a few years ago and is back on the way down."

After the UK's election ended in a hung parliament, there was a social media backlash against Prime Minister Theresa May, which prompted Harry Potter author JK Rowling to tweet "femaleness is not a design flaw".

Ms Clark said unfortunately women need to develop a thick skin for public life.

"I developed one over the years. You can't take any of it personally," she said.

"You have to keep tunnel vision on why you're doing this and why you stick with it, because if you opened your ear to a lot of the mindless things that are said you'd end up being personally crushed."

Topics: world-politics, women, documentary, new-zealand

First posted June 12, 2017 21:53:53