"During my time in the European Parliament [from1999-2010 - Lucas had to resign on being elected to the House of Commons], I supported calls by the European Commission for action on the disgracefully low level of women in the boardrooms of major companies," says the green activist - who is probably less well known as a supporter of a more interventionist approach to gender equality.
Talking exclusively to HR magazine, the doyenne of the Women's Environmental Network (WEN) says: "The Green party has long supported introducing boardroom quotas to improve the representation of women and address the substantial pay gap. When only one in eight directors of FTSE 100 companies are women, it is clear something needs to change."
Lord Davies suggested firms must "aim" for 25% female boardroom representation by 2015 - doubling the current 12.5% of women who are directors in the FTSE 100. But this compares poorly to Norway, where 40% of boards must be female.
Lucas says: "Sadly, if the Davies report is anything to go by, it is unlikely Britain will look at introducing quotas to address persistently low female representation." It is a prospect the Brighton MP is genuinely upset about.
"I do find it depressing that the progress of women in the upper echelons of business seems to have stalled," she says testily. "While large strides have been made in the past decade towards increasing female participation in the workplace, boardrooms still remain highly male-dominated."
Businesses dislike quotas, arguing that if they are under pressure to hire someone because they are female, that jeopardises their ability to hire the best talent. But Lucas argues the example set by Norway has proved quotas are workable. Britain is falling behind the rest of Europe on this matter, she says: Iceland has passed a 40% quota law for firms that comes into effect in by 2013. Similar ones will apply in Spain and the Netherlands by 2015, while France is also preparing legislation.
"We need to see talented people in top positions - and there is no question of prioritising gender over genuine ability to do a job well," Lucas admits.
"But this would be an easier argument to make if it were not for the obstacles many talented women come up against at senior levels. Experience has shown that quotas do not have to lead to a poorer quality of candidate. When Norway called on firms to have 40% representation of women on their boards, contrary to expectations of there being a shortage of suitable candidates, there was a wealth of high-quality female applicants."
She adds: "EU research has shown that boards comprising a variety of people from different backgrounds and experiences are more effective."
Far from seeing quotas as a port of last resort, Lucas simply believes more women on boards is both good for business and a worthy social and economic pursuit in its own right.
Even this is an uphill struggle, she admits: "The lack of female representation in UK politics is in itself a reason why positive change on this issue is proving elusive," she says. "Men outnumber women five to one in the UK parliament, putting us 53rd in the world for parliamentary representation of women. This means the sorts of policies we need to be able to address the specific problems that women face - policies such as quotas to increase female representation on boards, equal pay audits and improved rights for flexible, temporary and part-time workers - are not being given the attention they deserve."
Trying to do her bit, Lucas has spoken in 63 parliamentary debates this year - including one in February on parliamentary reform, where she was in characteristically strong form about proposing changed sitting hours. "Is it not beyond the wit of this parliament," she demanded, "to arrange our sitting hours so that people can do enough preparation for their committees? Do we want this House to set an example by working relatively family-friendly hours - or not?" she asked. "If we do, other things will fall into place."
Lucas believes wider reform will be needed before broader conversations around female board representation begin to feel natural. "The continuing pay gap between men and women is a demoralising reality for many women in both the private and public sector and is a huge obstacle to greater equality at later boardroom level," she observes. "Childcare provision falls far short of what is required and can differ greatly from one employer to the next. Weak paternity rights only add to the pressure women can face when trying to juggle family and professional life."
One thing she definitely doesn't agree with, however, is the notion women 'deselect' themselves from the boardroom-level talent pool by choosing to pursue either motherhood or less of a (male-dominated) long-hours culture. "If talented and competent women aren't putting themselves forward for top jobs on company boards, we need to ask why," she remarks. "Some men work hard and put in long hours, others do not; just as some women choose to work long hours and others do not. Surely, what employers should be looking at is less about long hours and more about how an individual makes best use of their time?
"Given more than half of the UK population is female, it seems obvious women should play a far greater role in decision-making at the top of companies," she continues. Lucas says a point often missed is that a more representative board is also a more agile and insightful board: "Boards ought to reflect the population as a whole because a company that wants to understand and communicate well with all of its consumers needs to listen equally to female voices. Aside from questions of fairness and equality, this is also about changing the sort of male 'group-think' - particularly in the banking and financial sectors - that led us into economic meltdown."
Lucas argues removing 'male-think' also extends to the way companies and the media often over-egg the hiring of the first 'female CEO' in a business - as if it were some epoch-making moment that a woman could get to this position.
One firm to tread this delicate ground recently was Japanese brokering house Nomura, which in March, according to BBC News, 'made a very bold move by appointing its first female CEO, Junko Nakagawa'. "In an ideal world, you wouldn't need to make such a song and dance every time a company hires its first female CEO, because it would be a more common occurrence," says Lucas, but on balance she argues that "until we see more women taking up positions at the senior level, it is important to highlight success where is it achieved".
So, despite her lukewarm reception of what Davies had to say, does Lucas hold much hope for the immediate future? "I have doubts a voluntary system [to ensure equality in the boardroom] will be strong enough to encourage real change," she says, honestly, but despondently.
She still does have hope: "There will always be debate over the perceived differences between men and women, but the important thing is that the Government and businesses alike fully understand the negative impact of under-representation of women in the economy and society," she says. "They must ensure equality of opportunity and reward at every rung of the ladder. Equal pay audits and improved rights for flexible, temporary and part-time workers would be a good start - as well as improved childcare provision and far stronger paternity rights, to allow men and women more flexibility in terms of child-rearing.
"In the 21st century, I am not sure it is useful to play up difference and reinforce stereotypes, when the real problem is inequality. Each individual brings with them their own unique set of experiences, skills and ways of working, and businesses must accommodate all that."
It is clear the MP for Brighton Pavilion will keep on keeping on.