According to the school's headteacher Mark Thomas the knock-on effect of this will be "that schools like Brymore, which currently offer land-based BTECs such as agriculture and horticulture, will be forced to drop them from the curriculum or risk being labelled 'unsuccessful'.
He added: "How can schools justify investment in school farms when these qualifications no longer count? The message is clear - land-based studies in schools are not valued."
The government has been reviewing school vocational education in the wake of the 2011 Wolf Report , which called for a simplified programme in line with labour market needs.
But recent proposals mean that hair & beauty and hospitality featuring among accredited BTECs, but not agriculture and horticulture, Thomas pointed out.
The petition, hosted by change.org, has reached 1,500 signatures since being launched earlier this month.
Established 60 years ago as a "secondary technical school of agriculture", Brymore boasts an organic farm, glasshouses and a walled garden. Though in the state sector, it teaches only boys, aged 13-17, nearly all of whom board.