Leaving the meeting leading Tory Sir Jeremy Bagge said: "I am not proud to be a Conservative because central office has deceived and betrayed us.
"These are strong words but that's how I feel."
A spokesman for the party said: "We are delighted that Liz Truss has been selected."
He added: "She is the right candidate who will work tirelessly for the local community."
Despite publicity about the affair at the time, information about it was not passed on to the local party which was told to use Google for the information if they needed it.
The decision to call a deselection vote caused tensions with the national party as Ms Truss is on David Cameron's A-list of would-be candidates designed to increase the number of women and ethnic minorities.
Conservative Sir Jeremy Bagge says he feels 'deceived and betrayed' by central office
Ms Truss, a councillor at Greenwich in south-east London and deputy director of the centre-right think tank Reform, was chosen as the constituency's parliamentary candidate last month.
Some South West Norfolk Tory members were angry she did not mention her affair during a selection interview.
They were also upset when the national party dismissed their unease about the original selection meeting and the fact that there had not been a local person on the list.
Ms Truss later gave an interview to BBC Look East and said: "It has been at times challenging. At times very interesting.
Buying house locally
"Of course there is an element of hurt. I have been sorry about the way things have turned out ... we are hoping to move forward.
"What the people here really want is somebody who is going to live locally and address the issues.
"I am already renting a place in Swaffham," she said. "I am going to buy a place in due course."
She added: "I want to work with everybody in the local party. All the people who supported me and those who didn't."
Ms Truss stood for the Conservatives in Calder Valley in West Yorkshire at the 2005 election.
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