The chair of the constituency association in St Albans resigned following the meeting, but the vice-chair is staying on.
Speaking after the meeting Ms Main said: "I'm absolutely delighted to have had the overwhelming support of the association meeting and I will be continuing with my work on behalf of the people of St Albans.
"And I'm truly grateful for all the messages of support that I've had coming in from people who aren't association members, who are the voters and representatives of St Albans."
The Tories have a majority of 1,361 over Labour in St Albans, with the Liberal Democrats close behind in third place.
The claims against Ms Main are being investigated by parliamentary standards watchdog John Lyon.
In May, the Daily Telegraph said she was claiming expenses for a constituency flat in which her daughter sometimes lived rent-free, and that her principal home was just 25 miles away in Buckinghamshire - a distance which her critics say makes her second, taxpayer-funded, constituency home unnecessary.
The MP said the original arrangement for the flat had been agreed by the Commons Fees Office.
The Conservative Party's scrutiny panel has deferred ruling on Ms Main's expenses while the probe is ongoing, although she claims she was cleared and that the panel had said her expenses were proportionate.
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