Image caption Ben Hopkins is heading for a US university

On the steps of Downing Street, Theresa May pledged to promote social mobility, to make Britain a country that works for everyone.

She pointed out that a white working-class boy is currently less likely than anyone else to go to university, and that the privately educated dominated the "top professions".

Her cabinet has the highest proportion of state-educated ministers since Clement Attlee was prime minister in 1945.

Justine Greening is the first education secretary to have been wholly educated at a comprehensive school.

However, promising social mobility and delivering it are different things, as previous governments have learned.

For decades now, the charity the Sutton Trust has been the standard-bearer for social mobility in Britain, developing schemes to help pupils from less advantaged backgrounds gain access to elite universities, and helping them into the professions.

The trust's chief executive, Lee Elliot Major, said the Brexit vote underlines the need for a broader policy now, as it exposed a divided country.

Many areas which voted Leave are those same areas where opportunities are fewest.

Mr Elliot Major said: "The political vote that we saw was a direct consequence of social immobility."

One of the Sutton Trust's newest schemes, in partnership with the Fulbright Commission, helps teenagers to apply to American universities and win scholarships to pay the fees.

It is very competitive. There are 10 applicants for every place.

Just 61 British students are going to the US on the scheme this year.

Ben Hopkins, aged 18, from the village of Wheaton Aston in Staffordshire, will soon be heading for Bowdoin in Maine, where he has won a scholarship. It is one of the most highly rated liberal arts colleges in the US, with fees of $62,000 (£48,000) a year.

Image copyright Getty Images Image caption Ben Hopkins worried whether he would fit in at Oxford

Ben does not come from a privileged background. His father is a machinist, his mother a teaching assistant.

Neither went to university. The family live in a modest, though immaculate, home, on the outskirts of the village.

South Staffordshire is one of the more affluent parts of the Midlands, with a lower rate of unemployment than the national average.

It is a Conservative area. Nearly 65% voted Leave on 23 June. Those I spoke to cited fears over immigration.

Ben's mother, Tracy, told me he had always been very committed to his schoolwork, and he perseveres until he gets something right: "He's a perfectionist."

She said she wasn't a "tiger mother". Ben had always set his own pace. Both parents are very supportive of their son and proud of his achievement.

Ben told me his teachers had helped him greatly. Some gave up their own free time to give him extra lessons.

He was a pupil at the local comprehensive, Wolgarston High, in the nearby market town of Penkridge. It is rated "good" by Ofsted, and improving. It currently gets some of the best A-level results in South Staffordshire.

Every year, some pupils go to Russell Group universities, and sometimes students go to Oxford or Cambridge.

However, Ben told me that when he visited Oxford he wondered whether he would fit in, as so many students seemed to have gone to private school.

Image caption Headteacher Philip Tapp says there is very little in the local area to inspire and raise aspirations

Adam Simmonds, head of sixth form at Wolgarston High, said others occasionally felt the same, as there is a strong sense of community in this part of South Staffordshire, and some 18-year-olds do not want to leave.

"Sometimes it's a powerful draw, their experiences in this locality, and they don't want to give that up to go to, well any university, actually," he said.

"We've had students with three As at A-level who've decided to stay at home because they like staying at home."

Though Stafford is just over an hour from London by train, Ben had only visited the capital once before he went for the Sutton Trust assessment.

The school headteacher, Philip Tapp, said he was working to arrange more trips for all students. He said there was very little in the local area to inspire and raise aspirations.

So what made Ben such an exception? His family, his teachers and ultimately, himself. No-one told him about the Sutton Trust: he discovered it online.

Adam Simmonds described Ben, outgoing head boy, as an "elder statesman" of the school whom everyone respected and felt they could talk to.

Lee Elliot Major, chief executive of the Sutton Trust, urged the new government to consider how to extend social mobility to help more people.

He said; "We can pick talent and then catapult it into opportunity, as with our US programme where you have amazing young people who are going to the Ivy League and other leading universities.

"But what about those areas that are left behind? What about the children who don't go on those programmes? And I think no-one at the moment has got the answer to that."

The new government is considering reversing the ban on new grammar schools, as a way of promoting social mobility. But that's controversial - many argue it will not work.

David Skelton, of the conservative think tank Renewal, said he thought a more sophisticated and complex approach was needed now. He said: "1950s England should not be our model."

He suggested more streaming in schools could be effective, and he endorsed the comments of the new minister for skills, Robert Halfon, who has said apprenticeships should be more highly valued and more could be done to improve vocational and technical training, such as that provided by university technical colleges.