There analysts say that if the pace of change remains the same as it has done since 2011, poor pupils will not catch up until 2070, it shows.
This year, 51% of the poorest pupils reached the expected level in their national end-of-primary school tests.
This compares with 70% of their better-off peers, leaving a gap of 19 percentage points
Residents can check how schools in their area have performed through the BBC's postcode search
Overall, Wirral pupils perform close to the national average for those grouped as state-funded schools and then all-schools