A "sea change" in the University of Oxford's admissions is expected with the launch of two schemes aimed at helping disadvantaged pupils.
The free programmes will be for bright but poor pupils who are offered a place to study at Oxford but struggle to meet the final requirements, or need help making the transition.
According to the university, by 2023 one in four Oxford undergraduates will be from the UK's most under-represented backgrounds.
The announcement comes as elite universities are under increasing pressure to widen access and make sure that students from poorer backgrounds are not put off from applying.
Oxford: widening access for disadvantaged students
One scheme, Opportunity Oxford, is aimed at pupils from more disadvantaged socioeconomic backgrounds.
It will begin from the next admissions round and will involve the introduction of a study programme for up to 200 pupils who have applied in the normal way and are on course to gain the required grades, but need additional support to transition successfully from school.
The scheme will comprise structured study at home, plus two weeks of residential study at Oxford just before the start of the undergraduate term.
The other scheme, Foundation Oxford, will be a full-year programme offered to students who have experienced personal disadvantage or severely disrupted education.
The scheme aims to open up places to students with high academic potential who, owing to their circumstances, are not yet in a position to make a competitive Oxford application.
Eligible students could include refugees and children in care or who have care responsibilities themselves.
Once in operation, offers for Foundation Oxford will be made on the basis of lower contextual A-level grades, rather than the university's standard offers.
The participants will all be based at Oxford colleges and, provided they successfully complete the programme, will move on to the undergraduate degree for which they were admitted.
The vice-chancellor of Oxford, Professor Louise Richardson, said: "This is a sea change in Oxford admissions.
"Colleagues from across the university, its colleges and departments have united behind a commitment to accelerate the pace at which we are diversifying our student body and ensuring that every academically exceptional student in the country knows that they have a fair chance of a place at Oxford."
The university says the programmes will offer places for up to 250 state-school students a year, representing 10 per cent of Oxford's UK undergraduate intake.
This is a significant change for the university, aimed at boosting the proportion of students coming to Oxford from under-represented backgrounds from 15 per cent of the current UK intake to 25 per cent.
Sir Peter Lampl, founder and chairman of the Sutton Trust education charity, said: “The scale of these programmes is really impressive.
“It’s good that Oxford are offering a more intensive foundation-year programme alongside a lighter-touch one.
“Many poorer students just narrowly miss out on places because they haven’t quite got the grades required. This will give a wider pool of students access to one of the world’s great universities.”
He added that Sutton Trust research has shown that many poorer pupils with strong school grades simply do not apply to Oxford or Cambridge. So, he said: “It’s crucial that these programmes are targeted at the right young people by working closely with schools and colleges.”