Longer school days could help boost the results of poorer children by giving them somewhere to do their homework, a cross-party group of MPs has suggested.
In a new report, the Commons Education Select Committee said that new guidance is needed on how extended school days can help youngsters from disadvantaged communities.
It also called for the Government to examine which incentives would encourage good teachers to work in disadvantaged schools, arguing that schools serving poor white communities "need a better chance of winning".
The recommendations come in a new report by the committee on the under-achievement of white working-class children.
It warns that these youngsters are falling far behind their classmates and their potential will be left "unlocked" if swift action is not taken to improve their achievement in school.
Figures show that just under a third (32%) of poor white British children got at least five C grades at GCSE, including English and maths last year, compared with 61.5% of poor children from an Indian background and 76.8% of poor children from a Chinese background.
At the same time, the gap in results between poor white children and their richer classmates has hardly changed in the last seven years, the report says, and the attainment of poor children from other ethnic backgrounds is improving faster than that of poor white children.
The committee also found that white British students from disadvantaged families spend fewer evenings per week doing their homework, and have a higher absence rate from school than many other ethnic groups.
In the past children who left school without decent exam results would have spent their working life doing routine manual work in factories, now they are more likely to end up as "Neet" (not in education, employment or training), it added.
"This problem must be tackled by ensuring that the best teachers and leaders are incentivised to work in the schools and areas that need them most, and by providing better advice and guidance to young people," the report says.
"Schools face a battle for resources and talent, and those serving poor white communities need a better chance of winning.
"Poor white children in rural and coastal areas have been "unseen" for too long; unless such steps are taken, the potential of white working-class children will be left unlocked, and the effects of the current trend will continue to be felt beyond the school gates."
The report calls for Ofsted to publish a best practice report on longer school days to give schools advice on how extended hours can help poorer children.
"The current trend towards longer school days presents and opportunity for schools to provide space and time for students from lower socio-economic backgrounds to complete homework, which may particularly benefit white working-class children," the committee said.
The report concludes that there are many reasons for the under-achievement of poor white children, including "matters in home life, school practices and wider social policies".
It adds that it is clear that schools can make a "dramatic difference" to disadvantaged children.
Committee chairman Graham Stuart said: "Poor white British children now come out of our schools with worse qualifications than equally poor children in any other major ethnic group. They do less homework and are more likely to miss school than other groups.
"We don't know how much of the under-performance is due to poor attitudes to school, a lack of work ethic or weak parenting. What is certain is that great schools make a significant difference in turning poor children's education around.
"The problem of poor, white British under-attainment is real and the gap between those children and their better-off class mates starts in their earliest school years and then widens as they get older.
"However, we also know that the effect of attending an outstanding school is transformational for poor children because it doubles their chance of success at GCSE."
The report came as Ofsted chief Sir Michael Wilshaw warned that the gap between white British children from poorer families and those from other ethnic groups must be closed to catch up with the world's leading nations.
"Immigrant communities are doing very well educationally and it should be recognised that they've added value to this country's performance," he said in an interview with The Times.
Poverty was all too often used as an excuse for failure by white working-class families, he added, saying: "It's not about income or poverty. Where families believe in education they do well. If they love their children they should support them in schools."
A Department for Education spokesman said: "The over-riding objective of our reforms is to improve the attainment of the poorest children in society - and we are already seeing real improvements.
"We have made it easier for all schools, not just academies and free schools, to extend the length of the school day. This can transform long-term under-performing schools, demonstrated by the likes of Great Yarmouth Primary Academy.
"Dozens of brilliant sponsors are turning around weak schools, which often have challenging intakes, and there are now a quarter of a million fewer children in failing secondary schools than there were in 2010.
"We also introduced the Pupil Premium, now worth £2.5 billion a year, so schools and headteachers have the resources to raise standards among disadvantaged children