The Green Party is has called for a "Green New Deal" to tackle the duel challenge of climate change and the economic slump.
Speaking at the launch of their election manifesto, "Fair is worth fighting for", in Brighton this morning, party leader Caroline Lucas MEP said she believed her party was "on the edge of a breakthrough" into Westminster politics.
Lucas is the favourite to take the south coast seat of Brighton Pavilion from Labour, giving the party its first ever Westminster MP.
The Greens came a close third at the last election, securing 9,530 votes compared to the Tories who got 10,397.
Labour won the seat with 15,427, a majority of 5,030, but the current MP David Lepper is not contesting this election.
The party is also targeting Norwich South, with candidate Adrian Ramsay hoping to unseat former home secretary Charles Clarke who has a majority of 3,653.
And they are looking to snatch the London seat of Lewisham Deptford, currently held by energy minister Joan Ruddock.
If successful in gaining all or some of their target seats, the Greens said they would not vote to "prop up" a Conservative government in the event of a hung Parliament.
Lucas dismissed David Cameron's attempts to make his party more environmentally aware as a public relations stunt, and said they had simply "polished up" their green rhetoric for their manifesto.
The Tories were guiltily of "diminishing the ambition" of environmental policies in the European Parliament, she added.
She also attacked the Labour Party for not doing enough on the environment.
"Labour thinks that more nuclear is the answer, they are not moving anywhere fast enough towards cutting emissions," she said.
And Lucas dismissed the idea that voters unhappy with Labour and the Conservatives would turn to the Liberal Democrats, especially in Brighton, arguing the Lib Dem vote had "collapsed".
"If you want the real thing, you can afford to vote for the real thing here," she said.
Unveiling their manifesto, Lucas said it was wrong to think the country had to choose between saving the environment and saving the economy.
"We demonstrate you don’t have to have a false choice between the environment and economy," she said.
"There are ways of tackling both of those things at the same time."
Calling for a "Green new deal" she said it was an indictment of a Labour government that after thirteen years in power Britain was "more unequal" than it was in 1997.
Lucas said that the Greens were offering a "fairer more effective" way of tackling the deficit through "radical tax reform", rather than "sharpening our axes" in preparation for "savage cuts" as the other parties were.
Among the manifesto pledges are plans to increase the minimum wage to 60 per cent of average earnings, increase the basic state pension to £170 a week and introduce a 50p income tax rate for those earning above £100,000.
"In a country that is more unequal than so many in Europe it is time that the wealthy pay more," she said.
According to their manifesto, their "immediate priority" is the creation of an extra million jobs and training places within a full year of operation of their plan, the Green New Deal.
It would consist of a package of measures including workforce training, investment in renewables, public transport, insulation, social housing and waste management
The Green Party is fielding more than 300 candidates across the country, a record in its 30-year history.
