Children from the lowest income households who live in some of the most disadvantaged areas of the UK leave secondary school having made almost two years’ less progress than their wealthier peers living elsewhere, according to a new report.

The Guardian reports that the findings are based on a comparison of student progress in six regions of the country which have low rates of social mobility, with pupil progress elsewhere in England.

The report, entitled Ambitious for Every Child and published this week, follows a commitment by the education secretary Justine Greening of £60m investment in six “opportunity areas” – Norwich, Blackpool, Derby, Oldham, Scarborough and West Somerset – to try to boost social mobility rates which remain stubbornly low.

The report states that among disadvantaged children, the progress gap in these 6 regions has “grown dramatically” since 2011.

The study found that long-term disadvantaged children, defined as those who were on free school meals (FSM) for 80% of their time at secondary school, were 20.1 months behind by the age of 16 compared with non-disadvantaged children across England.

But even living in one of the “opportunity areas” had a negative impact. Children from better-off households in those areas are falling behind their peers nationally, making almost five months less progress than pupils elsewhere.

The report was authored by new education charity Ambition School Leadership (ASL), which identifies and develops high-quality school leaders and places them in challenging schools in order to improve attainment and extend equality of opportunity to children across the country.

The charity also report that the progress gap in the government’s six opportunity areas has grown every year from 2010 to 2015 – increasing by 3.6 months for non-disadvantaged pupils and 8.3 months for persistently disadvantaged students.

Schools in these areas were also more likely to see a fall in Ofsted’s grading of their leadership and management. Around 18% of schools rated as having “good” or “outstanding” leadership in 2010 fell to “requires improvement” or “inadequate” by 2016.