Party leader Natalie Bennett has told supporters the Greens are the only alternative to the “indistinguishable” big Westminster parties.
She predicted a change in British politics as voters look to parties like hers and UKIP for “new answers”.
The party is training activists at its annual conference in Brighton how to emulate UKIP’s recent success.
In her speech, Ms Bennett attacked the coalition over the economy and Labour for not providing an alternative.
“There is one alternative to the three virtually indistinguishable neoliberal parties,” she told party members.
“That alternative is the Green Party.”
The Green Party in England and Wales want to ban all advertising aimed at children and plan to set out proposals to boost the economy and end food poverty.
They will use the conference to discuss how to tackle fuel poverty and oppose the privatisation of the NHS and Royal Mail.
Ms Bennett said the health service was being “torn to shreds” and “handed over to handful of profit-at-any-costs, multinational health companies.”
To applause and cheers she told supporters: “We will not rest until we’ve expelled every last corporate blood sucker from our NHS.”