Research compiled by BBC News shows women are under-represented in many of Britain's top jobs - from the boardroom and the courtroom, to politics and policing. But do they only have themselves to blame?

"There is nothing to stop you being whoever or whatever you want to be. The only thing stopping you is you."

So says Emer Timmons, a businesswoman of 20 years' experience, promoted seven times in the past six years.

But figures gathered by BBC News show women still hold fewer than a third of the most senior positions in the UK.

In politics this figure plummets to a fifth, and it is even lower in the top 100 companies.

But if, as Ms Timmons argues, women now have a huge opportunity to succeed, why are they still largely invisible at the top table?

Media playback is unsupported on your device Media caption Cherie Blair on what can be done today to get more women to the top

The 43-year-old president of BT Global Services UK believes there are so few lifestyle obstacles, it can only be down to the individual.

"Sometimes people still think they should be handed things - but they've just absolutely got to have more confidence in their abilities," says Ms Timmons, who is married with two step-children.

Research by the Institute of Leadership and Management on ambition and gender found different attitudes between men and women.

"Compared to their male counterparts, they tend to lack self-belief and confidence - which leads to a cautious approach to career opportunities," a 2011 study suggested.

Image caption Emer Timmons hopes to become chief executive of a FTSE-100 company

But leadership psychologist Averil Leimon says this approach begins long before women enter the corridors of power.

At age 11, girls and boys have very similar ambitions and attitudes to risk, she says, but as they go through puberty, girls reduce risk-taking.

"Each gender is conditioned from an early age to behave in different ways - girls to keep quiet and boys to shout out.

"We train our girls to work hard and get A*s. When they get into an organisation, women continue to work hard, they do well and they wait to be picked for the next role. That's not how organisations work - they are not necessarily meritocracies."

Women "get stuck waiting to be picked" and find this "hard and unfair", she says.

Men will say "pick me, pick me", even if they are not quite up to scratch. "If a man has got 40% of what it takes to do a job, he knows he's ready - a woman will wait until she's pretty perfect and then think, 'Am I ready for this?'

We still have a long way to go to ensure that women are better represented, not only at every level in politics, but at every level in society too Kate Green , Shadow Women and Equalities Minister Women 'still missing' in top jobs

"Just that action sets women back."

That might even explain the lack of female candidates for high office.

Diane Abbott MP was the lone female contender for the Labour leadership.

"I, as a woman, really agonised and thought 'Is this right?', and obviously all the other women in the party did too because I was the only one prepared to go for it, whereas the men who ran really didn't give it a second thought," she explains.

"Women tend to think of the reasons why they shouldn't do something, whereas men are not hindered by that level of introspection."

Leimon does not think women are their own worst enemies. Instead, the problem is more to do with perception.

The issue is "strongly rooted in our Anglo-Saxon culture which still thinks it's a little bit odd and special that ladies want to go out to work", she says.

But barrister Cherie Blair believes men are subject to stereotyping too.

Men do not want to be cast as "the chap who goes hunting in the forest, brings home the bacon and has nothing to do with the bringing up of his children".

She adds: "The roles between the sexes are now much more fluid."

Image caption Averil Leimon said women still face a "huge unconscious bias"

Then there is the parenthood factor.

Ms Timmons says with technology enabling women to work anywhere and more free childcare available, now is the time to aim for the top.

You can have it all, agrees Mrs Blair, just not at once. But a change of attitude is needed.

"We should stop pulling women back for the decisions they make in their early child-bearing years as somehow being full-stop decisions."

Siobhan Freegard, founder of Netmums, says you cannot have a top job and a family life. Ambitious mothers are obliged to get nannies and cleaners, effectively "outsourcing" family life.

Leimon's take is that squaring ambition with having children is a matter of personal choice, but that these decisions are no longer just a "female issue".

But why is it important to have women at the top table?

Apart from the fact women make up half of the population of Britain, girls outperform boys at school and make up 60% of university graduates.

There is growing evidence that women in senior positions are good for business, and there are those who question why Rwanda, Afghanistan and Iraq far outshine the UK for women in positions of political power.

Much has been made of boardroom quotas, all-women shortlists, role models and mentoring, but how else can women achieve the top jobs?

Few appear in favour of taking to the streets to start a new wave of feminist protest - change, it seems, needs to be more delicate than that.

"There is a place for just being a lot more bolshy but there is also a case for us being subtle and influential and just changing opinions politely," says Leimon.

And her advice?

"Women need to build their confidence and go for it - and haul another woman up with them."