THREE years ago the political establishment was shaken to its roots when Green Party won two seats in the European Parliament and increased its local council representation to 19 seats.

It seemed to be a party whose time had come, appealing to the imagination of the young and the disillusioned voter who wanted to do something about pollution and environmental damage at local and international levels. But while the fire flared brightly through 1995 and early 1996, with the party averaging about 4 per cent in the opinion polls, it appears to have lost momentum in the past year.

Recent Irish Times/MRBI opinion polls have given the party a core vote of 2 per cent, which can translate into a 3 per cent overall rating. But, so far, there has been no "lift" in the run up to the general election.

Party members hope this weekend's annual conference will provide the spark to rekindle public interest. The party will launch its election manifesto tonight and introduce its 23 candidates to the press at a function in Dublin's newly refurbished Mansion House. Tomorrow, it will deal with such issues as food and agriculture, economics and taxation, honesty in politics, health, crime and drugs and environmental protection at its conference in Malahide, Co Dublin.

Anxious to put the image of a single issue party behind it, the Greens will be taking tough and uncompromising approaches to such tricky political issues as industrialisation, intensive farming, taxation and the growing imbalance between rich and poor countries.

Selling policies which may reduce the rate of economic growth and standards of living through the introduction of carbon, fertiliser and pesticide taxes will be difficult. But in advocating a shift of taxation from income to resources, the party offers the phasing out of PRSI, a 10 per cent starting rate for income tax, a widening of bands and a top tax rate of 50 per cent. It also advocates radical change from road to rail in transport policy and the closure of Sellafield.

Trevor Sargent TD believes there is a growing international and global crisis over pollution and energy use which must force people to question traditional economic policies and the benefits of EMU.

The party's only TD envisages steady growth for the Green Party, rather than a spectacular breakthrough. Many of the party's Dail candidates would be using this general election to establish a strong electoral base, he feels, in advance of the local elections.

JOHN Gormley, a former Lord Mayor of Dublin, says they will be asking voters to examine their quality of life to see if it has disimproved in tandem with rising living standards, and to draw conclusions. Realistically, the party could hope to win three or four Dail seats in the election, he said, but if the tide was with it, that could rise to seven.

Fifteen years after its foundation, the party is no longer regarded in political circles as a bit of an ecological joke. The European and local elections put a stop to that. It is regarded as a serious threat.

Just how seriously that threat is being taken is evident in Fianna Fail's response. For the past two years the party has been consulting widely on the preparation of an environment policy under the direction of Noel Dempsey. And it was hardly coincidental that the launch of that comprehensive and worthy document should precede the Green Party's annual conference by a matter of days.

Because of the Greens, no party conference is now complete without a special section of the leader's speech devoted to the environment. And the Progressive Democrats have staked their claim to the area through Mary Harney's contribution to a smog free Dublin and the establishment of an Environmental Protection Agency.

Just because the party has a new sunflower logo doesn't mean it is politically friendly. It is now firmly in the business of getting and holding power. It takes its lend from Germany, where the Greens form the third largest party; from Finland, where they are in a coalition government, and from Denmark, where they are a political force. The party will enter the general election with a shopping list of change and, if it holds the balance of power in the next Dail, it will negotiate on policy matters.

The party has already put a negotiating committee in place. And provision has been made for a special delegate conference which would ratify any future deal on the formation of a government.

There are difficulties about leadership. The party believes in devolution but, as Mr Sargent says: "We aren't happy with the cult of leadership because it distracts from a full debate on policies."

Irish parliamentary politics revolves around party leaders, with a rigid pecking order involving spokesmen and spokeswomen and whips. Greens are not yet prepared to swallow this. However, there are indications of flexibility in nominating a "party representative" rather than a leader, and in appointing a party whip.

Such issues may give rise to intense debate among delegates this weekend. In spite of that, the party is anxious to dispel suggestions of a Loddite tendency. Sustainable development is its catchcry. And Greens point to their growing use of teleconferencing facilities as evidence of their modern and progressive approach to politics.

If the general election is as closely fought as the latest opinion polls suggest, then the Green Party could hold the balance of power - and enjoy a place in the sun.