UNTIL recently, the layby outside the US listening station at Menwith Hill was full of the ramshackle caravans of a peace camp. Today, it's virtually empty - just a couple of lorries and a mobile caf selling bacon butties. In the distance, the enormous white spheres of the spy base rise out of the mist and traffic trundles past.

But then two battered vans - one red, one white - pull up. The doors slide open and 20 or so women jump out, unloading garden furniture and banners. Some are carrying metal poles and bits of wood, one clutches a tambourine.

It's bitterly cold, the puddles are frozen, and everyone's muffled up in hats and scarves. A couple of them light a fire. Minutes later, a policeman comes over and asks them to put it out, but they're adamant they have permission and he eventually moves away to keep watch from the warmth of his van further along the layby.

This is the first of a two-day protest against America's Son of Star Wars programme - a controversial space defence system, which, if it goes ahead, will utilise British bases, including Menwith Hill near Harrogate. The protest coincides with the 20th anniversary of the encirclement of Greenham Common, and many of the women here are Greenham veterans, including Helen John.

Originally from the South-East, she moved to Yorkshire in 1993 specifically to start a women-only protest group. By 1996, it was attracting women from across the country, many of whom were living in caravans outside the base. "At first, people just thought it was an early warning system. They didn't know its true activities until we started drawing their attention to it," she says.

Ironically, the women were too far ahead of the their time for their protest to have any impact. Most people dismissed their ideas as fanciful, but as the prospect of war with Iraq moves ever closer, some are starting to listen.

"People thought we were mad but everything we said was going to happen has happened and I think people are taking it seriously now. I just hope it's not too late," says Helen.

The camp remained in the layby until 1998, when it closed following complaints from the residents of nearby villages. Since then, there has been sporadic activity outside the base. Last year, Greenpeace campaigners broke through the perimeter fence, reinforcing the message Helen and her colleagues had been putting out about the threat of global domination by the US military.

As the current protest moves into its second day, the women plan to blockade the A59 and they haven't ruled out other direct action.

"We do sometimes have to do something illegal to make people listen. It's worth it if we can get them to understand how serious the situation is," says Helen, who has been to jail several times over the years.

She first became involved in the peace campaign during the early 60s when she was working as a midwife near London. "We needed an incubator but we didn't have the funds, and then I heard about two Harrier jump jets that had crashed and were replaced at a cost of £14m each.

"It would only have cost £25m to put a new incubator in every midwifery establishment in the country and that was when I started to look at the word defence and what it meant. I realised I didn't need the bullet or the bomb. I didn't need the military but I did need other things that the money being spent on militarism could have been used for."

She makes the parallel with the ongoing firefighters' strike.

"It is going to cost £10bn to upgrade these stations for Star Wars and America is going to give us nothing. It's ironic when you think that £1bn would give the firefighters their pay rise." Her enthusiasm hasn't dwindled over the years. In fact, she's just as determined now as she was in the 60s, but her anger is tempered with experience. When a policeman comes to ask if he can search her van, she doesn't bat an eyelid. She's seen it all before and nothing fazes her.

She stood as an independent candidate in Tony Blair's Sedgefield constituency at the last general election. "Mr Blair came into power with a lot of hope from the people but he has let them down. In everything he has done in his leadership, he has deferred to the US. That is not in our long-term interests or his. It is certainly not in the interests of his baby son." But while she is critical of the Prime Minister, she is positively vitriolic about George W Bush, the man she calls 'The Godfather' because of the way he controls American politics. "After September 11, people are afraid to speak out. This man has barely any majority but they're terrified of him in case they're accused of supporting terrorism. He's brainwashed the people into his way of thinking.

"America wants to be able to say who will live and who will die, who will eat and who will starve. They want to control the world's food and mineral resources and allowing them to have bases here is one way of doing it.

'WE will regret it, the same way we regretted doing business with Hitler until three weeks before the Second World War. Everyone in the country could see it was wrong but the politicians wouldn't listen."

But the protest isn't just attracting veterans like Helen. Finn Mackay has been involved with the peace campaign since 1993. A diminutive figure, barely visible beneath an enormous coat and warm hat, she is just as well-informed and articulate as her older colleague.

"I lived near two Greenham women when I was younger and I think that's how I became aware of everything. When I was 17, I left home and came to live here, at the only women's peace camp in the country," she says. She is only 26, too young to remember Greenham Common properly, but she speaks about it as if she had been there, so deeply is it ingrained in her consciousness.

"Women have been traditionally excluded from the political process but Greenham Common was a chance for them to take that power back, so are these demonstrations. They can influence the decisions that affect them. Women are standing up to say: 'Not in our time.'"

As the temporary camp begins to take shape, the diversity of the group taking part becomes obvious. Coaches are due to arrive in a couple of hours, bringing up to 200 women to the site from across the country, but even among the core group, there are women from both Helen's and Finn's generations, and one even has her baby with her. Local accents mix with the distinctive intonation of a group of women from Sweden and Norway, who have been campaigning against Son of Star Wars in their own countries.

But despite barriers of language and age, they all pull together, braving the wind to shin up trees to erect their banners. Some boil water to make tea, others take photographs and film footage to record the occasion.

Finn says: "There is a real sense of camaraderie and friendship and I wouldn't expect anything else. I think the thing about this is that it affects everybody, whether they live here or on the other side of the world. That's why so many different people want to be a part of it."