WI teams up with Mumsnet to boost campaigning power

As twin pillars of middle-class British womanhood, the online forum Mumsnet and the Women's Institute influence the lives of millions. Now – in a move that will strike fear into politicians and other targets of their wrath – the groups are preparing to join forces.

The WI has long been the largest women's voluntary organisation in the UK, with 205,000 members, while the 1.2 million users of the website Mumsnet have turned it into a powerful campaigning force, with politicians regularly taking to the site in the hope of wooing the women's vote.

Both have individually flexed their muscles with significant impact. In the latest example, a £1.25m advertising campaign proclaiming "Career women make bad mothers" was pulled from 4,000 billboards around the country last week after a backlash led by vocal Mumsnet posters. The Prime Minister was roundly mocked in the media last October for supposedly failing to disclose his favourite biscuit to Mumsnetters – who are described by their detractors as smug, wealthy women with a penchant for Boden clothes and organic food – while his rival David Cameron was derided for being too slow at responding to questions.

The WI – traditionally considered a clique of elderly "jam and 'Jerusalem'" types – has recently thrown itself into campaigning on domestic violence and the imprisonment of people with mental health problems, as well as the precipitous decline of the UK's bee population.

The groups have agreed in preliminary meetings that they could campaign jointly on issues ranging from the environment to body image. Users of Mumsnet will meet in London this week to discuss the next steps, while the WI will put the matter to its policy committee next month.

Justine Roberts – who founded Mumsnet with the television producer Carrie Longton in 2000 as a forum for mothers to share advice – confirmed that talks with the WI are ongoing. "The more people we can align with the better, and the WI could be good for us to work with," she said. "The important thing is to create as much pressure as possible to bring about the change which you want to create. Instead of 10 different organisations arguing for the same thing but with their own slants, it is far better to work together."

Ben Page, chief executive of Ipsos Mori, said the move will give the organisations more clout: "The effect they have will depend on them getting behind an issue that the majority of their members agree with, and which chimes with the rest of the public."