The latest Ashcroft National Poll shows that support for the Green Party has grown three points to 11 per cent while Ukip's has dipped by one to 15 per cent.
The results give further credence to the party as leader in England and Wales Natalie Bennett campaigns to be involved in the televised debates before May's election.
However, Ashcroft's poll is in stark contrast to one from ComRes for the Independent on Sunday which showed Ukip up on 18 per cent and the Greens on just three.
Meanwhile, the Conservatives' lead in Lord Ashcroft's poll has slipped five points from 34 per cent to just a one point lead over Labour, whose support has remained steady.
Lord Ashcroft, who sits in the House of Lords for the Conservatives and published his poll on ConservativeHome, noted that while his polls usually show lower support for the two main parties this combined total (57 per cent) is the lowest yet. It is also the first time the poll has shown under 30 per cent support for both parties at the same time.
An increase in support for the Greens is seen as detrimental for Labour as Bennett's party are seen to attract a lot of their voters from Labour ranks, while a decrease in support for Ukip would be beneficial to the Conservatives for similar reasons.