Green party's Natalie Bennett: 'Money must be found for energy investment'
13 September 2013 Last updated at 07:35 BST
Green party leader Natalie Bennett has insisted money "has to be found" for investment in clean energy sources, ahead of her party's autumn conference in Brighton.
She told BBC Breakfast's Louise Minchin that gas sources, such as shale gas - obtained through the controversial 'fracking' method - was the "high price option".
Ms Bennett is due to address the conference on Friday afternoon and is likely to promote the idea that the Greens have concerns stretching beyond the environment.