Green Party conference in Bristol: Darren Johnson
7 September 2012 Last updated at 13:19 BST
The Green Party's Darren Johnson claimed the party was "on the up" since gaining an MP and coming third in the London mayoral election.
Mr Johnson, a London Assembly member, told Chris Mason that at its conference in Bristol this weekend the party would set out plans for a "fairer and greener Britain".
Natalie Bennett was elected as the new leader on Monday and will address the conference on Friday afternoon.