Adam is a Senior Researcher for the Conservatives on the London Assembly. He writes here in a personal capacity.

In his recent speech, Prime Minster David Cameron channelled the spirit of Benjamin Disraeli when he said that his would be a “One Nation Government” that extended opportunity to all.  Here the Prime Minister was making very clear his ambition to place social mobility at the heart of this Government’s agenda.

Prioritising social mobility taps into a well-established conservative tradition. It was Winston Churchill who first said that the Conservative Party must be the party of the ladder, not the queue; and Michael Gove, perhaps the greatest living education reformer, has said that conservatives must be “warriors for the dispossessed”, completely focused on improving social mobility for the very poorest. But has social mobility improved since 2010?

At the beginning of the last parliament, 23.8 per cent of state-educated A Level students went on to study at the top-third of universities – now it is 23 per cent. The gap between those from the most advantaged and least advantaged backgrounds currently employed in professional positions has increased from 16 per cent to 19 per cent. Further, the proportion of the lowest earners that have experienced wage growth over the course of the last decade has remained stable at 12.5 per cent. Even if social mobility hasn’t worsened over recent years, it has at least stalled.

In an effort to address the issue of lagging social mobility, the last two governments have rightly prioritised school choice and competition. Recent academy reforms have empowered teachers and created a demand-led system of schooling through the Free Schools programme. There are now 4,256 academies and 292 Free Schools in England – roughly a fifth of all schools. This greatly adds to parent choice and frees teachers to teach.

Yet, while the job of academising the English school system is far from the complete, the next round of reforms should move on from increasing school choice to improving school standards. It is only by improving the latter that the attainment gap between rich and poor pupils can be truly closed.

The Coalition Government did introduce a policy to do just this. The Pupil Premium provides additional funding to schools to help raise the attainment of disadvantaged pupils, which is classified as those in receipt of Free School Meals (FSM). For this financial year, schools will receive a £1,320 Pupil Premium per pupil, taking the total Pupil Premium budget to £2.5 billion. This intervention, while well-intended, has not yet had the desired effect on attainment.

Since the Pupil Premium was introduced in 2012, the proportion of FSM pupils achieving A* to C in English and Maths at GCSE has fallen from 36.8 per cent to 36.3 per cent. In addition, the proportion of those in receipt of FSM at 15 who went on to achieve A Levels has remained stable at 21.9 per cent since the introduction of the Pupil Premium. Again, even if the situation is not worsening, it is not improving either.

For the Pupil Premium to work it must be a targeted intervention, but there are two key reasons why it cannot be targeted accurately. Firstly, as the majority of schools have seen a real-terms cut in per-pupil funding over recent years, the pupil premium is not additional money. Secondly, the Pupil Premium is not ring-fenced and is therefore subject to competing budgetary demands. This dilution of the Pupil Premium is exactly why the National Audit Office called on the Government and schools to do more to “optimise value for money”.

Instead of a targeted intervention on social mobility and school attainment that can’t, because of the reasons mentioned above, actually be targeted, we need an incentive that very specifically rewards schools for improving attainment. Instead of a vague Pupil Premium, we need an ‘Oxbridge Premium’ that would financially reward those schools that secure places for their poorest pupils in the top, Russell Group universities.

Introducing a payment-by-results element to school achievement would create a clear link between state school attainment and financial success. Such a system would ensure monies are only given to schools once excellence had been evidenced and social mobility improved. An ‘Oxbridge Premium’ need not completely replace the current Pupil Premium, but it would be a better way to focus resources in a time of ongoing thrift.

As it stands, just 0.1 per cent of FSM Year 11 pupils that took their A Levels went on to Oxford or Cambridge universities. Further, just 8 per cent of state educated undergraduate students went to the top Russell Group universities. This is a particularly sorry state of affairs when you consider that Oxbridge graduates will, on average, earn a £7,500 per year higher starting salary than those who attended low-ranking universities.

A CBI report published last year suggested that, if we close the social mobility gap, we could add £8 trillion to the economy over the lifetime of all children born today. That amounts to one per cent growth in GDP every year. Using a new ‘Oxbridge Premium’ to financially incentivise schools to secure places for their pupils in the top universities would be a good, market-based approach to school excellence that would help spread prosperity. Not only this, it would allow the Conservative Government to close the attainment gap, improve social mobility and challenge the deep-seated dogma that insists ours is a ‘party for the few’.