In an address to Greens' autumn conference, party leader Natalie Bennett said Britain was a low-wage economy and people deserved "a decent return on their labour".
Under the plans, wages would rise by £1.15 to £7.65 an hour next year before increasing each year until 2020.
The party also proposes a "wealth tax" on those with assets of more than £3m.
The party, which currently has one MP, is promising a "progressive alternative" to the austerity agenda which it says the other Westminster parties have all embrace
The Green Party shows its economic illiteracy, offering fantasy left-wing policies. They want to make businnesses pay out more on wages as well as pay more tax. How are they supposed to produce the wealth this country needs?
There is nothing green about these policies. This is a socialist agenda, not an environmentalist agenda. If the Greens were serious about their environmental concerns, they would be making friends with business, seeking to encourage them to become more environmentally concerned. Instead, they want to impose new costs on business, an obstacle that will get in the way of adapting industry to environmental concerns.