Education officials are urging Lincolnshire County Council to close one of the county's smallest schools.
A report recommending the closure of St Bede's Catholic Science College in Boston will go to the council on 7 June.
Under the proposal, the 350-pupil St Bede's would close and become part of Haven High Technology College.
The school has struggled with poor exam results and was first put in special measures by Ofsted in 1999.
The new merged school would operate from both sites from September 2011.
A 700-name petition against the closure has been sent to the county council.
Officials said it was a struggle to provide "a broad and balanced curriculum" because it was so difficult to recruit qualified specialist teaching staff to a small school.
In August 2008, St Bede's was the second lowest performing school in England for the number of pupils who attained five GSCEs at grades A* to C, including English and maths.
Officials said the move will retain the number of secondary school places in Boston while improving educational standards.