A new study by FFT Education Datalab has found disadvantaged pupils are less likely to take key stage 1 Sats tests than their advantaged peers.
The study found that 12 per cent of disadvantaged pupils did not take the reading test, compared to 5 per cent of their more advantaged counterparts, while 7 per cent of disadvantaged pupils were not entered for the maths test compared to 3 per cent of non-disadvantaged pupils.
Disadvantaged pupils also tended to score three scaled points less than their peers in reading and maths, which Datalab suggests "may be an underestimate because they are twice as likely not to even take the tests due to them working at a lower level."
For disadvantaged pupils born later in the year, the difference was more pronounced – 17 per cent of underprivileged pupils born in August were not entered for the tests.
The news follows reports from last year that the gap between poorer pupils and their classmates at the end of Reception year had widened for the first time in four years.
Data from the Department of Education last year revealed that 57 per cent of pupils eligible for free school meals were judged as being at a good level of development at the end of Reception, compared to 74 per cent of all pupils.
The report found pupils who did not have English as a first language were also slightly more likely not to be entered for the tests – 7 per cent of EAL pupils were not entered for reading compared to 6 per cent of pupils with English as a first language, while 4 per cent of pupils with EAL were not entered for maths, compared to 3 per cent of pupils with English as a first language.