Commenting, Neil Leitch, chief executive of the Early Years Alliance, said:
"Research study after research study has shown that if you want to close the attainment gap between disadvantaged children and their wealthier peers, you have to start in the early years.
"For all the government's rhetoric on improving social mobility, the EPI research shows that rather than improving, progress in this area has actually stalled.
"The early years sector plays an absolutely pivotal role in supporting children's early development and, in the long term, their life chances. It's time the government recognised this and committed to giving the early years sector the investment it needs to ensure that all children, regardless of their background, have the best possible start in life."