Caroline Dinenage campaigned on her local credentials
TV presenter's daughter Caroline Dinenage has won the contest to replace an MP who attempted to claim for a floating duck house on his expenses.
Ms Dinenage, daughter of veteran TV host Fred, will fight Tory Sir Peter Viggers' seat in Gosport, Hampshire, after a postal ballot of all voters.
It is only the second time in the UK that a so-called "postal primary" has been used to select a prospective MP.
Sir Peter, 71, will stand down at next year's general election.
He has been the town's MP since February 1974 but was forced to resign by Tory leader David Cameron after his expenses claims were published by the Daily Telegraph and found to include £1,645 for the duck island.
The winner, a local councillor and businesswoman, said during her campaign that she understood the area's problems as she had lived there all of her life.
The 38-year-old mother-of-two secured 4,892 votes, or 38.6%.
James Bethell, a venture capitalist based in London, came second with 2,965 votes.
Sam Gyimah, an entrepreneur, came third with 2,867 votes, and Julia Manning, an eye specialist in the NHS, came fourth, polling 1,935.
It is understood staging the primary - which gave everyone on the electoral roll in Gosport the chance to have a say on who should be the town's Conservative candidate - cost the party around £38,000.
With a turnout of 17.8%, or 12,659, that equates to a cost of £3 per vote cast.
But the Conservatives say they are pleased with how the primary has gone, describing the turnout as "a tremendous endorsement of the process."
The selection method was first used by the party in July in Totnes, Devon, to find a replacement for another expenses row MP, Anthony Steen.
Totnes voters selected a local GP, Dr Sarah Wollaston, as the Conservative candidate, ahead of two local Tory politicians.
The Gosport turnout was down on the 24.6% in Totnes.
Ms Dinenage said she hoped the open primary would help the constituency put its association with the expenses scandal behind it.
"That was the whole point of doing it. It was an opportunity for people to have their say and try a new, more open and transparent approach to politics," she told BBC News.
She said the open primary system favoured candidates with "a genuine affection for, and understanding of, the area" rather than being part of the Westminster establishment.
Commenting on the outcome, Conservative Party chairman Eric Pickles said it was a "fantastic result" for Gosport and the Conservative Party.
He said: "The fact more than 12,000 people turned out to have their say is great news for local democracy.
"We are entering a brave new world in parliamentary selections. This is the second time we have run an all-postal primary which really does give power to the people.
"I would encourage our opponents to consider this radical change as a way to reinvigorate our political process. It is vital we make every effort to rebuild people's trust in their politicians."
Foreign Secretary David Miliband has backed the idea of primaries, but other senior Labour figures have been less enthusiastic, citing concerns about costs and the impact on local constituency parties who have traditionally selected candidates.
Similar concerns have been expressed by the Lib Dems, although some influential voices in the party are thought to be in favour of primaries.