Esther Rantzen will bid to become MP for Luton South at the next General Election, she announced today.
The TV presenter said she had decided to stand as an independent despite warnings from political experts that there was "no chance" of victory.
"This is an exciting and slightly petrifying new step for me," she told the Press Association. "There is a feeling in the air that people want a choice.
"We are still feeling, all of us, angry and distressed about the expenses scandal."
Rantzen has been weighing up whether to stand on an anti-sleaze ticket since sitting Labour MP Margaret Moran was embroiled in controversy over her Commons allowances.
It emerged in May that she had claimed £22,500 to treat dry rot at a property in Southampton - 100 miles away from her constituency.
Mrs Moran has since announced she will not defend her 5,650 majority at the next General Election.
Rantzen will formally launch her campaign at a press conference in Luton this afternoon.
She said: "Every political pundit tells me I cannot possibly win, Britain never votes for independents.
"All the experts tell me that it is a crazy idea.
"However, the people I meet are unanimous in saying that I should stand."
The former That's Life presenter went on: "I cannot predict how the mood will be when the election actually happens, and I am humble enough to recognise that, when experts tell me I haven't got a chance, they might be right.
"But I hope I could be really good for the people of Luton South."
Rantzen talks to the BBC