Westminster's glass ceiling.

Women’s political influence and female politicians’ public profile has never been greater. Margaret Thatcher was voted the third most inspirational person of the last century, beaten only by Richard Branson and Nelson Mandela, in a recent Mori poll for the BBC.

There are more women MPs in the current parliament than ever before and five women sit in the cabinet.

It’s a start. But women are still under-represented. A closer look at the figures reveals why. Women were first given the vote in 1918 and the first female MP was elected that year, though like all Sinn Fein MPs, Countess Constance Markievicz did not take her seat at Westminster.

For most of the century, the number of women in the Commons hovered between 20 and 30 until the 1987 general election when it increased to 41 and then to 60 in 1992. Labour introduced a quota system for women candidates in time for its 1997 landslide victory, when the number of women MPs doubled to 120, 101 of whom were Labour.

But even today’s record figure means that women make up less than a fifth of all MPs. And though Margaret Thatcher broke two records in becoming the first woman to be prime minister and have the longest period in power in the 20th century, during that time, she only appointed one other woman to a cabinet post – Baroness Young, who was Lord Privy Seal and Leader of the House of Lords in 1982/83.

Dr Sarah Richardson, an expert on women and politics from the University of Warwick, says powerful women politicians are few and far between.’You have to ask how the election of women MPs has translated into cabinet posts or positions of influence,’ she says.

‘Margaret Thatcher stands out; Betty Boothroyd had influence and there are a number of women in the cabinet but, especially in key posts, it hasn’t translated into anything concrete. It’s not a very auspicious picture.’

The culture of the House of Commons, with late-night sittings a regular occurrence, is perceived as a bar on women. Tess Kingham, the MP for Gloucester who first entered the Commons in 1997, announced last year that she would not stand again because Parliament’s culture, which she likened to a ’19th century gentlemen’s club.’

The parties say they are trying to encourage more women parliamentary candidates. ‘As well as its quota system for the last election, Labour has two groups Labour Women and sister organisation Emily’s List promoting women in public life. Val Price of Emily’s List, which was set up by MP Barbara Follett, says there are a number of obstacles facing women. ‘We call them the four Cs – confidence, culture, childcare and cash. Cash is where Emily’s List comes in – to pay for travel, a good set of photographs, even a decent suit.’

The body was set up in 1993 to support and give grants to women seeking public office. In 1997, it handed out #30,000 to 72 women, about 15 of whom, including Tess Kingham, became MPs. In the last year it has awarded grants to about 30 women to help them through the candidate selection process.

‘Emily’ stands for ‘early money is like yeast,’ Price says. ‘Early money, at the point of seeking selection, is an essential ingredient for any woman who wants to break through the glass ceiling.’

Marney Swan, chairman of Conservative Women, does not believe in positive discrimination, concentrating instead on women’s lack of confidence and the attitudes of candidate selection committees.

‘I think women often don’t believe they can do it,’ she says. ‘Men have greater confidence – at 19 they believe they can rule the world. Women need more encouragement.

‘A difficulty I find with younger women is that the constituency selection committees wonder how they are going to juggle their families with politics, though goodness knows some do. When they are in their forties, had their family and perhaps run a business, when they would make fantastic MPs, the selection committees often ask themselves “do we want someone that old?” But I don’t think these are problems that are just confined to the Conservative Party.’

Despite the efforts of bodies like Emily’s List and Conservative Women, the likelihood of more women entering the Commons at the next election is fading. Richardson says the obstacles placed before women in party politics have led many to throw their weight behind single issue groups instead.

And despite its success in 1997, Labour has now abandoned its quota system.

Price acknowledges that the number of Labour women MPs is likely to decline.

‘Women-only shortlists helped us enormously, but the recent selection process was held without such a mechanism so inevitably there will not be many new women in Labour held seats. Depending on how the next general election goes the number of women MPs will drop from 101 into the 90s.’

Smith is optimistic numbers will rise – but it will happen slowly. ‘It has taken a long time for women to be accepted at the top of law and in medicine,’ she says. ‘In politics it’s also a gradual thing – but if we push too hard it probably won’t happen.’

The Labour Party website is at www.labour.org.uk, while the Tories can be found at www.conservative.com.