Parents with children at Manor High in Oadby voted 452 to 343 against opting out, in their third poll in four years.
The school was only the second in the country to ballot on GM status three times. The other - Preston Manor High in the London borough of Brent - opted out on its third poll.
Manor High parents overwhelmingly rejected the GM option in their first ballot in May 1991, when just 27 per cent voted in favour of opting out.
Two years ago the parents were more narrowly split. On a 64 per cent turn-out, 55 per cent of the parents voted against opting out, compared to 45 per cent who backed GM status. The rejection this time round was 100 votes more than the ballot in 1993.
Peter Thompson, from the Keep Manor Local campaign, said: "This is the only school in the country to have voted no three times.
"I think this result is even more significant, because parents voted not to opt out even though they were threatened with losing four teachers and with their children being sent home at lunchtime to save money.
"It becomes clearer that parents don't like the idea of opting out of the local education service."
The school would not comment on the result.