Unknown who may be the political sensation of 1999

SHE IS 38. She is married with two children. She is unknown to the general public. And in just over five months, she may be one of the most famous politicians in Britain. Caroline Lucas stands an excellent chance of becoming the first British Green Party member to win a seat in the elections to the European Parliament.

The introduction of proportional representation in the June poll means that after 25 years as the Cinderellas of British politics, the Greens could at last go to the political ball in the assemblies of Brussels and Strasbourg.

Thanks to the forthcoming closed-list system of PR, in several of Britain's 11 new European electoral regions the Greens are in with a chance of at least one of 89 seats on offer, and Dr Lucas, an Oxfam policy adviser, stands the best chance of all. Not only does the electoral arithmetic work best for her - under the new system she needs only 8.3 per cent of the vote in her South-East region to get elected - she is regarded by many observers as an outstanding candidate for a party whose policies have in the past been seen as distinctly cranky. Dr Lucas is a radical, but a reassuring radical. She has a long history of involvement with CND, the women's movement and Third World issues, as well as holding many senior posts in the Green Party itself, but she is also well-presented and engaging, married with a family and holding down a responsible job.

Ask her why anyone should vote Green and she replies: "Because there's no better way of putting pressure on the other parties to put environmental and social issues at the top of the agenda than by getting some Greens elected."

The Greens are against European monetary union, global free trade, the relentless pursuit of economic growth, and nuclear weapons. Theyfavour stronger animal welfare controls, no new roads, green taxes to replace income tax and a state-guaranteed basic income for everyone.

Their election would give renewed political significance to environmental issues, which are regarded by the Government's engine room, the 10 Downing Street Policy Unit, as worth very few votes for Tony Blair's re-election in 2002, compared with the economy, health and education. They would also provide a properly radical alternative for Labour voters feeling Tony Blair has merely stolen the Tories' clothes.

Handled properly, the June poll could mean a significant comeback for a party that in the past decade has succeeded only in marginalising itself by internal squabbles, and at its worst moments becoming a national joke - very much against the international trend. Green parties are thriving across Europe and are members of national coalition governments in France, Germany, Italy and Finland.

The Greens reached their British high point in the European elections of 1989, when they secured a remarkable 15 per cent of the national vote and made environmental issues politically significant for the first time. But Britain's first-past-the-post electoral system denied them any seats. Their biggest electoral successes to date have been seats on local councils (they hold 29).

Furthermore, after 1989 the party proceeded to implode. Its two best- known and most charismatic faces, Jonathon Porritt and Sarah Parkin, led a movement to try to turn it into a streamlined election-fighting machine but were defeated by grassroots activists suspicious of a powerful "centre". Both dropped out of active politics (they now share the running of an environmental charity, Forum for the Future) and since then the party has faded from the national consciousness.

Now it does not even have a leader, a position that remains anathema to the party grassroots. Instead it has two Principal Speakers, who are Jean Lambert, a part-time teacher from London, and Mike Woodin, a psychology tutor at Balliol College, Oxford, and an Oxford city councillor. Both are able and experienced figures, backed up by an experienced executive committee, a small but professional secretariat and nearly 5,000 committed, paid-up members.

Under the closed-list system voters choose a party rather than a person, with the parties drawing up their own lists of candidates. Seats in each region are then allocated according to the proportion of votes each party wins.

The percentage required to win one seat varies in the 11 regions from a high of 20 per cent to a low of 8.3 per cent. This latter figure, and some others, look distinctly achievable to the Greens.

In national polls, the Green Party is nowhere: when people are asked who they would vote for in the next election it is lumped in with "others" and does not even register. But in local elections, the picture is very different. Last May in the 240 seats where it stood outside London, it averaged 7.07 per cent of the vote, up from 4.88 per cent in 1997, and in some areas it did very much better.

In the South-East Euro region, where the party needs only 8.3 per cent of the vote to send Dr Lucas off to Brussels, it averaged 9.88 per cent in the 47 seats in which it fielded candidates.

And in the London region, where the party needs only 9.1 per cent of the vote to make Jean Lambert an MEP, it averaged 10.05 per cent in the 257 seats in which it stood.

"When you see what the Labour Party's performance on the environment has been to date, it's increasingly clear that you need to elect Greens to put pressure on them to deliver," Dr Lucas said.

"Our overriding message to people is that there's no better time to vote Green, and that a Green vote is no longer a wasted vote."