The Westminster parliament will have a Green MP by the end of this decade, predict environmentalists.

Speaking to the BBC News Online service, the Greens claim that support grew at the last general election and party membership grew for the first time since the 1990s.

The party has already had seen success in elections to the European parliament and the Greater London Assembly, but has always struggled under Westminster's "first past the post" electoral system.

Despite this, Greens saw their share of the vote increase from 2.9 per cent in 1997 to 9.3 per cent in 2001.

Chair of the party's chief executive, Penny Kemp, said that the aim was to have a Green MEP representing virtually every region, with a Welsh assembly member elected by 2003.

"We are making sure that local parties are very well organised and prepared to fight in a high profile campaign in the local elections," she said.

"One of the problems of the green party in the past is that different sections of the party have tended to develop their own policies. We want the parties to have a small number of core issues that they campaign on."

The Green Party have recently focused on other policies other than environmental issues. At a recent conference, the membership voted in favour of legalising prostitution, while deciding to join the anti-Euro campaign.

Darren Johnson, the Green GLA member, said: "We are building up some significant support from ex-Labour people. Many traditional Labour voters are so disillusioned with the way the party has gone."