Many pupils who get a fortnight of home study for their GCSEs are using it as "video game leave", a minister says.
Boys do not do as well as girls at GCSE
Education minister David Miliband says home study ruins the chances of many boys getting high grades.
The minister is now looking into banning the practice, which is currently at the discretion of schools.
He told the Times: "I do not see why... students should be left on their own to figure out the best way through one of the most testing times."
"Study leave...for a lot of boys especially... has become video game
The Department of Education maintains schools that have banned all study leave have dramatically improved grades.
But the National Union of Teachers believes schools would struggle to find enough room or teaching staff to accommodate the pupils if they were in school during the equivalent period.
Constant efforts are being made to address girls' regular outperformance of boys at both GCSE and A-level.
It is thought peer pressure and other cultural factors may be behind much of the difference.