Analysis By Nick Assinder BBC News Online political correspondent

The Green Party has come a long way since its sensational breakthrough in the 1989 European elections.

Greens have transformed image

It came from nowhere to seize 15% of the vote and, arguably, put environmental issues top of the political agenda.

Thanks to the UK's first-past-the-post voting system, however, it failed to win a single seat in the European parliament in that election.

The system has since changed to PR and the party now have two MEPs who sit as part of a 35-strong group of Green members in the Brussels parliament.

But in those intervening 16 years, the party has struggled to achieve anything like the breakthrough it would dearly love to repeat.

Six seats

On 10 June, however, they are hoping to capitalise on the growing opposition to the two big parties over their support for the war on Iraq.

Greens hope for more Euro seats

And its leaders are cautiously hoping to win six seats this time around.

The party has also transformed itself from those early days when it was widely viewed as a fringe, even slightly eccentric, one-issue group.

It now presents a far more professional, mainstream face and has developed polices across the range of government responsibilities.

And there are plenty of signs that the green message strikes a chord with voters, particularly younger ones.

The problem for the Greens, after 1989, was largely that the other main parties moved decisively onto their patch.

Big players

Having raised the issue of the environment, party leaders had to sit on the sidelines as the other parties put it at the centre of their manifestoes.

Voting Green 'will send Blair a message on Iraq'

That required a broadening of the party's appeal and policies.

But it still offers a radical message which is hard to sell in the UK.

And it probably attracts protest votes from the other parties which may not translate into longer-term support.

There is an added complication this time as there are fewer UK seats up for grabs after enlargement of the EU.

None the less, the new-look party believes it is slowly building support and has joined the big players, certainly in the European parliament.