Mainstream parties were routed in an astonishing council by-election result just days before Prime Minister Gordon Brown is expected to call a general election.
The Greens' Rachel Eburne captured a Tory seat at Mid Suffolk District, also humiliating the Liberal Democrats and Labour.
She polled 61 per cent of the vote at Haughley and Wetherden with a 33.2 per cent net swing from the Conservatives.
Labour, which had a councillor in the ward until 2003, polled just 32 votes.
The Lib Dems, a close second last time, only managed 51.
The result comes a week before another by-election challenge for the Green Party in a Lancaster City Council ward where they shared seats with Labour in 2007.
Green leader Caroline Lucas is seeking a General Election breakthrough for her party.
She is fighting Brighton Pavilion where party city councillor Keith Taylor polled 9,530 - 21.9 per cent - in 2005.
Ms Lucas, an MEP, would need a 7.3 per cent swing for victory.
Press Association analysis of the 2007 city council elections in Brighton Pavilion put the Greens in the lead just 221 ahead of the Tories, with Labour trailing more than 1,000 votes further behind in third place.
Another possibility for the party has emerged in recent years in Norwich South where it took first place in last year's Norfolk County Council polls. Labour, the party of sitting MP and former Cabinet minister Charles Clarke, came in fourth.
Analysis of a small sample of four comparable results in March suggest a projected 7 per cent nationwide Tory lead over Labour.
In the case of the Mid Suffolk contest, the comparison is with the 2003 council elections when Labour last fought the ward.
Result: Mid Suffolk District - Haughley and Wetherden: Green 444, C 176, Lib Dem 51, Lab 32, Ukip 25. (May 2007 - C 354, Lib Dem 309, Green 122). Green gain from C. Swing 33.2% C to Green.Reuse content