Seven years ago, Baroness Thornton was volunteered by her peers to take on the task of galvanising support for a new social enterprise umbrella body. It is clear why she was their first choice.
"I wrote to everybody I could think of who might be interested and invited them to come to a meeting at the House of Lords," she says. "I thought they were going to tell me to get lost. What actually happened was that everybody came."
Thornton's commitment even extended to using her parliamentary expenses to pay for a part-time administrator for the fledgling Social Enterprise Coalition.
The coalition has grown and strengthened into an influential body that has swayed policy makers and achieved greater recognition for its members. But Thornton has decided the time has come to step down as chair. "It took a huge amount of emotional energy, and I would bring that baggage to the next stage of development," she says. "Instead, I want to look at what should happen next."
Future developments will be built on firm foundations. Social enterprise has become an entrenched ideology within the Office of the Third Sector, culminating in last year's social enterprise action plan. Ministers such as Patricia Hewitt, the former health secretary, and Hazel Blears, the communities secretary, have converted to the cause, and Cabinet Office minister Ed Miliband has made the greater understanding of social businesses a personal crusade.
One of Thornton's greatest strengths is her ability to combine passion and enthusiasm with an acute political awareness, and she is candid about the attractions of social enterprise. "I think the time was right," she says. "The Government was looking for ways to deliver services that were not private and not public, but could be done by people taking control of their own workplaces.
"I am a strong supporter of the voluntary sector, but this was about bringing disciplines of business and of the marketplace into supplying public services."
However, Thornton knows there is work still to do.
"Just because the Cabinet Office is driving the third sector stuff across government, it doesn't mean it is actually going to happen," she says. "It's a good start, but you have to then persuade a whole swathe of senior civil servants, junior ministers and other people that this is a really good thing, something they should put their time and energy into."
She also understands that it will take more than political will for social enterprises to be accepted by UK customers. "My ambition is for there to be a social enterprise formed on EastEnders or Coronation Street," she says. "Let's have a community-owned nursery or something. Wouldn't that be wonderful?"
Until the soap scriptwriters call on her services, Thornton has plenty to keep her busy. She has recently taken on chairships at the Innovation Exchange and the Improvement and Development Agency's third sector commissioning project, and plans to invigorate the All-party Parliamentary Group on Social Enterprises, of which she is also chair. She also intends to develop independent and credible research into social enterprise, possibly within a new institution.
For now, Thornton believes she has launched the coalition on the best possible path.
"I'm completely confident that this organisation is going to grow into the CBI or TUC of the social enterprise sector," she says. "In the next 20 years, we could be talking about a huge organisation for a very big sector of the economy that's really powerful."
2007: Chair, national programme for third sector commissioning advisory
group, Improvement and Development Agency, and chair, Innovation
2001: Founder and chair, Social Enterprise Coalition
1998: Labour and Co-operative Party life peer
1993: General secretary, Fabian Society
1981: Public affairs adviser, Co-operative Wholesale Society