Outdated, ruthless, rich and male: that is women's overwhelming and damning view of Westminster, according to a survey by the parenting website Mumsnet.

In a questionnaire that brings home just how disenchanted many female voters are with the current parliament, nine out of 10 of Mumsnet's members, who are 97% female, say they believe the political culture there to be sexist, while two-thirds believe success in politics is all down to what school or university you went to and the "old boys' network".

"It's quite stark," said Mumsnet founder Justine Roberts. "Of course I would say, yes, we know a lot of this, but the clarity of these results, the overwhelming strength of feeling, are quite remarkable."

When asked which characteristics would be advantageous in politics, 94% of respondents said ambition, 92% cited social connections, 86% said ruthlessness, 84% said being well-off, and 78% said being male.

On the question of which changes the 1,300 site users who responded to the survey would like to see in the UK's political culture, 84% backed the proposal from the Hansard Society earlier this year to vary the format of the notoriously rowdy prime minister's questions (PMQs), including introducing rapid-fire Q&As, more open questions and penalties for MPs who behave badly.

PMQs has become a symbol of all that critics feel is wrong with our male-dominated parliament, said Roberts. Half of the respondents thought it damaged parliament's reputation and 76% felt it was unprofessional and outdated.

The Hansard report in February found similar perceptions among the wider public. Dr Ruth Fox, director and head of research at the Hansard Society, who co-authored the findings, said: "PMQs is a cue for the public's wider perceptions of parliament. It provides a lot of the raw material that feeds their negative assumptions about politicians. The public think the conduct of MPs is childish and wouldn't be tolerated in other workplaces. They think politicians are simply not taking the issues that affect their lives seriously enough."

Some 59% in the survey wanted a "sin bin" for MPs who behaved badly at PMQs and 80% did not believe MPs conducted themselves well or that the televised Wednesday afternoon sessions were effective. But one of the most worrying findings of the self-selecting poll was that about 69% of women said they would not stand for parliament or as a local councillor, and 85% believed going into politics was not a family-friendly career.

Despite being unwilling to put themselves forward, however, 63% thought that more women in top political jobs would mean politicians would have a greater understanding of their concerns.

"That was the saddest thing," said Roberts. "People are so fed up. We know that the reason there is a lack of female representation in parliament isn't just down to sexism at the point of selection; there just aren't enough women prepared to put themselves forward. This is confirmation of how they feel and how strongly they feel. Things like the long hours and being 'on show' is rolled into the idea that it's all a bit male and shouty, but even male MPs have complained about the hours. The hours seem to revolve more around 50-year-old men who want to socialise than even among thirtysomething men who are dads and might like to have a family life."

Half (49%) said they were more likely to vote for a party with more female representatives and 64% wanted to see more citizen engagement (for example, through social media).

And many felt disenchanted with the political process: more than a third (35%) described themselves as disillusioned with UK politics, and saw it as irrelevant to many in the UK. Nearly half (47%) believed the British political system was not effective at achieving change to improve British people's quality of life.

The opinions are a chance to attract votes for the first party to react to women's concerns, however, with 78% of those polled looking for parties to address the gender issues in political culture and increase the family-friendly nature of parliament in manifestos.

"I think that the devolved parliament/assembly in Scotland and Wales do a much better job than Westminster. I am actually ashamed of Westminster and think it presents the worst possible image of Britain to everyone (at home and abroad)," said one respondent.

Another said: "The problem with PMQs isn't so much that it's shouty but that the so-called pinnacle of political debate in this country is two men trading petty insults and making nasty jokes about the other while the rest of parliament boos and cheers behind them. We may as well get some preschoolers to call each other poo-heads and be done with it."

If political parties have been slow to tackle the sexual inequality issue, there has been cross-party concern about the issue among female MPs. "We have to make politics look more like Britain," said Gloria De Piero, the shadow minister for women and equality. "No wonder most women think it's sexist and doesn't represent them when eight out of 10 MPs are men.

"When I've travelled around the country listening to women talk about politics they are quick to say they want it to be more representative. That means opening up our politics to let in more women and more people from working class backgrounds too.

"To most people, Westminster is a closed shop; as one woman, Sharon from Derby, put it to me, 'how do you become a politician? There's no advert in the local paper or jobcentre'."

Now, 22% of MPs are women, 147 out of 650. A third of Labour MPs (86 of 257) are female, as is 44% of the shadow cabinet. Three out of 27 people in the coalition cabinet, 48 out of 305 Conservative MPs and seven of 56 Lib Dems are female. "It cannot be right that there are more male MPs in the House of Commons today than the total number of women MPs ever elected," De Piero said.

Roberts agrees: "For ages now it seems we've all accepted that parliament is outdated, unrepresentative and sexist. We'd love the parties to stop paying lip service to this and to start taking concrete steps to get its house in order."

Mumsnet will be hosting a live webchat on the results of this survey with the minister for women, Nicky Morgan, women and equalities minister Jo Swinson and Labour shadow minister Gloria De Piero on Tuesday 24 June from 1pm to 2pm