New Zealanders in the United Kingdom could be crucial to the Green Party's success at this year's election.

Co-leader Metiria Turei is in London to speak to party members and woo potential voters.

The Greens have won an extra seat during the last three elections, once overseas votes and other special votes were counted.

London correspondent Annabel Reid told Rachel Smalley that has affected the balance of power.

"The last election interestingly enough, Greens, by winning another seat in the special vote, actually took a seat of National which denied them an outright majority."

Reid said housing is the issue on everyone's minds.

“Metiria is saying the people she’s been speaking to say that they care about climate change and what the government’s doing to address child poverty, but I do think people living in London in their mid-20s, mid-30s, they care about buying a house back home.”

LISTEN ABOVE AS ANNABEL REID SPEAKS WITH RACHEL SMALLEY