She uses her coffee as an analogy. 'You can put as much milk as you like in a cup of black coffee, but at the end of the day it still has black in it. It could come out at any time. The blacks and the Asians destroy the race.'
Isabelle Hernon has listened to the edict from on high. At last year's BNP rally, John Tyndall,the party's leader, emphasised the importance of motherhood and breeding. Isabelle is doing just that. A pretty, 38-year-old redhead, she has five children and believes she is carrying out the highest role in the party - the furthering of the white race.
Her hatred of immigrants began on the back streets of the Gorbals in Glasgow. Her childhood was tough; there was a shortage of parental affection and cash, and Isabelle wanted scapegoats. By the time she had turned 16 she had found a forum for her revulsion: the Scottish National Front. She switched to the BNP when she moved to London.
The party is guarded about its membership, but it is estimated there are 2,500 paid-up members. It is thought that fewer than 250 of these are women.
Isabelle's racism is multi-faceted. She says Jews, particularly those who are prosperous, don't belong in this country. But if they have no more than she does, they can stay - if they must.
She looks at me and says menacingly: 'For all I know, you could be Jewish.' She has not ordered her children not to talk to Jewish classmates, but there are few Jews in her part of Essex anyway. But she insists they stay away from Asian and Pakistani children, even if they're sitting at the next desk - a tall order when there are as many children from ethnic minorities as white children in her children's schools.
'None of my lot would ever, ever bring home a black or a coloured boyfriend or girlfriend. I've brought them up too well,' she says. Isabelle doesn't shop in the local corner shop owned by a family of Pakistani origin. Nor does she give her business to the greengrocers run by people of Asian origin.
As we talk an Indian man excuses himself and squeezes behind Isabelle's chair to sit next to us. Isabelle cringes and her face shows an expression of disgust. She starts to talk of her respect for Hitler and his 'enormous' achievements building autobahns and housing. 'He made people happy,' she says.
Smiling, Isabelle lists her own political achievements. 'I spoke at a National Front rally in Scotland. I had to have a police escort on horseback to protect me. I have given newspaper interviews, I have rallied, I have canvassed. I was the BNP candidate for Epping Forest in 1989.'
As she gets up to leave, Isabelle reiterates that she is petrified that blacks, Asians and Jews will overrun the country. 'You will admit they have more children than us,' she says, before rushing off to pick up her fifth from school.
Perhaps it is because she is the antithesis of a skinhead that the BNP has given Isabelle a high profile. No shaved head, no swastika, no jackboots. She is good for their image. Most BNP women are much more low-key about their activities.
Elizabeth Porter (not her real name), 55, is one of five women on the Isle of Dogs who proposed the nomination of Derek Beackon, the BNP member who recently won a seat on Tower Hamlets council in the Millwall by-election. She is at first intimidating, but the veneer is thin. 'You won't use my real name and address, will you?' She will talk as long as she can tape the conversation.
She says her paranoia is because of her increased vulnerability, as a woman, to attack. She is petrified by the violence in the area, particularly since Beackon's election. She claims that gangs of Asian teenagers come from Brick Lane and stand in wait for white children outside the local school. It doesn't seem to occur to her that even if this is true they might be reacting to years of discrimination.
At the core of Elizabeth's racial hatred is her resentment of positive discrimination. 'I'm sick of the situation. They started a new primary school here last year: 12 places for Asian children and eight for white children. It's just not fair.'
Ironically, she comes from a left-wing background. She was actively involved in the Labour movement until her son was in a fight with a black child. She claims her son was suspended, while the other child was let off. So she joined the NF and then the BNP. She sees her role in the party as that of a 'missionary in the jungle'. 'I try to convert people on the island to the BNP if they haven't quite made up their minds. I am not prejudiced though; how could I be with a black daughter-in-law?' How does Elizabeth cope with that? 'I don't see her as black. She's not too happy about me being a member of the BNP, but when she comes down here she sees I have a point.
'Stop immigration; stop importing diseases like TB. We've got it back on the Isle of Dogs because of them - the Pakis, the Bangladeshis and the Sikhs have raped and bled this country.'
She assures me her views are entirely her own, but refuses to be interviewed alone. It is an uncomfortable interview, crammed in her tiny, red Formica kitchen with her husband, son and nephew. At first she denies their involvement in the party, but later whispers that her nephew is an active member.
There is one other woman present - 35-year-old Jackie, although someone slips up and calls her by her real name. She has a large gold cross around her neck and a British flag on her lapel. She is the girlfriend of Elizabeth's younger son, but had no political involvement until a year ago, when she discovered her children were eating Indian food at school.
Her canvassing and rallying intensified as the by-election drew near, but she delivered propaganda material at 4am for fear of being recognised and attacked. Often she takes her boyfriend along to protect her. Jackie conducts her political activity on the Isle of Dogs in secret. She doesn't want the people she grew up with to know of her involvement.
'I was spat at once on my way to do my shopping - spat at by a half-caste boy. He called me an ignorant pig.' She believes the boy was aware of her politics and was spitting in retaliation. 'I don't want the thugs to know who I am. I don't want a petrol bomb through the window of my front room.'
Jackie's involvement in the BNP is contradictory. She says she is afraid of the violence of retaliation because of her children, but they are the reason for her political activity. 'If they grow up and meet someone around here, I don't want them to have to live in a slum - the Asians get all the good housing on the island.'
Jackie is thrilled about the election of Derek Beackon. 'I'll step up my activities now that things are more in the open. I'll do whatever the party tells me to do,' she says.
As the interview draws to a close, Jackie and Elizabeth discuss pseudonyms they could use for this article. 'Well,' says Elizabeth, 'they could call me Patel.' They roar with laughter and reach quickly to turn off the tape recorder.
Richard Edmonds, the BNP chairman, says he does not want journalists near 'his women'. He claims the party is very protective of them.
Tony Robson, a researcher from the anti-fascist magazine Searchlight, has a rather different view. He substitutes the word 'subordination' for 'protection'. He says that female defectors from extreme right-wing groups often tell stories of being subjected to misogyny and sexual abuse.
After two weeks of phone calls, I finally manage to get through the door of the BNP headquarters to meet a 30-year-old party member, introduced to me as Debbie Carter. She is mousy and dressed as though she has just walked out of a Laura Ashley shop.
She refuses to have her photo taken. 'They might call me a racist. It's not true, but they might call me one because of what you write. I can't take that risk, not with James,' she says, bouncing her blond, blue-eyed, two-year-old on her lap.
If Debbie doesn't consider herself a racist, what are her political beliefs?
'I believe in what the BNP believes in,' she says. She looks around the room we are in. On the wall are three posters. One depicts a goose stepping German solider with the caption 'Deutsche Nationalistische Front'. The second is a eulogy to French right-wing extremist Jean-Marie Le Pen. The third is a picture of revisionist historian David Irving with the caption 'La Mentira del Holocausto' - The Lie of the Holocaust.
Debbie doesn't say much about Hitler, but she does have an opinion on the desecration of a Jewish cemetery in Southampton in August, when more than a hundred graves were covered with swastikas and anti-Semitic slogans. 'The Jews did it themselves. They did it like they've done it before; they did it to make us look bad . . . but no, I don't really know any Jews.
'We are,' she says, 'living with the dregs of society.' She declines to define the term, but adds: 'It's not that I hate blacks, it's just . . .' And she discourses on the effects of immigrants on 'our' jobs, 'our' housing and 'our' benefits.
Debbie says her family had no interest in politics and her opinions developed after listening to items about immigration on radio programmes. I get rather a different impression. As we talk, Richard Edmonds and Debbie's skinhead husband keep appearing.
Debbie joined the BNP eight years ago. She claims it had nothing to do with her husband, despite the fact that she married him the same year. Many women are drawn to the movement in their late adolescence or early twenties. It may seem sexist to suggest that they have been influenced by right-wing talk in pubs and by their boyfriends, but research carried out by Searchlight has shown that this is often the case.
In her early days of involvement with the BNP, Debbie regularly joined street marches, but she does that less frequently these days. Because of James, she wants to avoid a high profile.
So what does she do for the party now? 'I distribute BNP literature for a start.'
Some of the literature is lying around the BNP's headquarters-cum-bookshop in Welling, south-west London. There are pamphlets entitled 'Did Six Million Really Die?' and copies of Spearhead, the party's magazine. 'It's a good magazine,' she says. Debbie helps out at the headquarters whenever she can find the time. There is a huge iron bar on the front door. All the windows are boarded up for fear of attack and there is no natural light. This is the springboard from which Debbie wants to create a better future for her child. She hopes he too will one day become a fully paid-up and active member.