When Miriam O'Reilly won her landmark age discrimination case against the BBC she said she was looking forward to returning to work for the corporation and unveiled plans for a support group for women facing similar difficulties.

The second of these ambitions will come to fruition this Thursday with the official launch of the Women's Equality Network, set up by Camilla Palmer, the lawyer who secured O'Reilly's victory. The former Countryfile presenter will be a patron.

But the return to her former employer did not go as anticipated. Given a new three-year contract by the BBC, which promised to overhaul the way it recruits and appoints its presenters, O'Reilly tore it up after only 12 months and a single TV project, a month-long daytime spin-off of BBC1's Crimewatch.

O'Reilly says she found herself sidelined by the corporation once again, blaming "seething resentment" among a small group of executives who were furious that she had taken on the BBC and won.

She was refused a return to BBC1's Countryfile and while she did appear on the BBC World Service, further work on BBC Radio 4, where she had previously presented editions of Woman's Hour and Farming Today, failed to materialise.

"When the BBC said it wanted to work with me again on the day of the tribunal victory I was very pleased about that. The whole aim of taking the action had been to go back to work to do the job I had been doing for over 25 years," says O'Reilly.

"But a small number of executives didn't feel that way, and it quickly became apparent to me that asking me back was a damage-limitation exercise rather than a wish to make amends and to address the problem of inequality at the BBC," she claims.

The lowest point after O'Reilly's return saw the presenter subjected to what she calls "playground name-calling" by a colleague. She declines to go into detail, beyond: "I was accused of not having a sense of humour about it but other people were appalled. It was pathetic.

"Of the people that I worked with, 99.9% of them treated me with tremendous respect and support and encouragement," she adds.

"But from certain individuals there was a seething resentment that I had won the case, executives who were really angry that I had challenged them and won resoundingly. They didn't like it that a woman had stood up to them. There was a huge amount of resentment there."

So in January this year O'Reilly left the BBC, fewer than 12 months after her tribunal win. She has had several book offers, including one about what happened to her at the corporation, but says her broadcasting career appears to be over.

The BBC's director general, Mark Thompson, whom she met to air her concerns before Christmas, told her he would be in touch in the summer with offers of further work if she wanted to come back, but O'Reilly appears not to be holding her breath.

Thompson has since admitted that the corporation does not have enough older female newsreaders and presenters. He described O'Reilly's tribunal win as an "important wake-up call" .

Thompson's impending departure – he has announced he will step down after the Olympics in the autumn – has prompted speculation that the BBC may have its first female director general, possibly its chief operating officer, Caroline Thomson.

"The issue of ageism will not go away when Mark Thompson leaves, it's in the public consciousness now," says O'Reilly. "Viewers are demanding the fair representation of women on television. It is a fundamental right; having female role models on television will have a huge impact on society."

O'Reilly, who is now 55, was one of four female presenters in their 40s or 50s (along with Michaela Strachan, Charlotte Smith and Juliet Morris) who were dropped in a revamp of Countryfile when it moved from Sunday mornings to a new peaktime slot in 2009.

An employment tribunal ruled in January last year that the BBC was guilty of ageism in removing her from the show, the first time an age discrimination case had been upheld against the corporation.

The tribunal heard that while still on the show O'Reilly had been told to be "careful about those wrinkles" and consider Botox. The ruling was a blow for the BBC and in particular for the then controller of BBC1, Jay Hunt, who is now chief creative officer of Channel 4.

The tribunal said that O'Reilly had been unfairly victimised, with several radio projects dropped because of a mistaken impression that she had complained to the press.

The comedian Rowan Atkinson made an outspoken and surprising attack on the discrimination case, saying it amounted to an "attack on creative free expression"; he said producers should have as much freedom to change presenter as they do to "change the colour of John Craven's anorak".

O'Reilly, in her initial reaction to Atkinson's comments, said: "At one time we didn't think black people should sit next to white people on a bus but fortunately we live in a fair and civilised society."

"I didn't run to the courts because I was dropped from Countryfile, as Rowan Atkinson presumed," she tells me. "It was because of what happened afterwards. I had accepted work in radio and that work was withdrawn because I didn't keep my head down."

O'Reilly had hoped to return to Countryfile but says it was made clear from the outset that was not going to happen. "I was told it would not be Countryfile by any stretch.

"I felt that I could work with them but from what I am told there were people who couldn't work with me. It became very apparent I would not be given work equivalent to what I was doing before I was unjustly treated."

The rural affairs show, with a younger presenting team led by Matt Baker and Julia Bradbury, has become a Sunday-night ratings hit, achieving audiences regularly in excess of 6 million viewers.

O'Reilly says it would have happened even without its youthful revamp. "People who say the audience is great because the BBC dropped these four older women, that's ridiculous.

"It is made for Sunday evening with all those images of the British countryside. We will never know [what it would have got] because we didn't get the opportunity to present it because of our age."

O'Reilly had expressed an interest in returning to Woman's Hour. Instead, she was offered four episodes of another Radio 4 show, Pick of the Week – along with four separate shows – but nothing materialised. Those responsible for the series said they were not told by a BBC executive that she was available until it was too late.

The Women's Equality Network is billed as an "online peer-to-peer forum where women facing discrimination in the workplace can share their experiences and support each other in a secure and confidential manner".

O'Reilly was drawn to the project because of the difficulties she experienced in speaking out at the BBC. The site, which has been contacted by women from sectors as varied as the military, banking, government and the health service – as well as the media – is intended to provide emotional as well as legal support.

"It is very isolating when you are in a situation where you feel you are being unfairly treated," says O'Reilly.

"There is really no one to talk to or go to, HR departments or colleagues, it just doesn't work. A lot of women I have spoken to in the last few months, once they start talking about it there are repercussions. People start to see you as a troublemaker."

Curriculum vitae

Age 55

Education Loreto Convent, Balbriggan, Co Dublin; Archbishop Ilsley RC comprehensive, Birmingham

Career 1978 trainee reporter, Kidderminster Times 1982 producer, BBC Radio WM 1985 presenter, Parent Programme, Education Programme, BBC1 1988 reporter/presenter, Midlands Today 1993freelance reporter/presenter Radio 4, 5 Live 2001 presenter Farming Today, Costing the Earth, File on 4, Woman's Hour, Radio 4 2001presenter, Countryfile

Article from The Guardian