Politics is often defined by what people disagree on. However, some issues are above party politics and it’s time that tackling social mobility became one of them. As politicians from three different parties, we sparred across the despatch box but now we’re coming together to build a cross-party consensus, focused on looking at the evidence of what works, to tackle inequality in education and boost social mobility.

Successive governments have made progress in boosting attainment and tackling poor performance across the schools system, but with the attainment gap between disadvantaged children and their peers stubbornly persistent it is clear more needs to be done.

With automation, digitalisation and huge changes to work, equipping our people with key skills for the future is vital. No longer can this just be about those who go to university. A true agenda for social mobility must relentlessly focus on ensuring that everyone gains a knowledge-rich and stretching education.

In the past, social mobility has been too narrowly defined, and too focused on helping a tiny few reach the top. The council estate to cabinet table story is well rehearsed. This unhelpful analogy fails to address the fundamental challenge we face: what’s known as the long tail of low skills.

Put it another way, if we look ahead to the needs of the economy in, say, 2022, forecasts show that there will be 9 million low-skilled people chasing just 4 million jobs, yet a shortfall of 3 million workers for the higher-skilled jobs. That’s before the effects of Brexit. While high-tech companies such as Google say we aren’t producing enough of the right engineering graduates for their growth, Britain has the third highest proportion of graduates in non-graduate jobs in Europe (with only Greece and Estonia behind).

These huge challenges require a new national mission, built on consensus and evidence, to turn them into real opportunities for our country.

The most effective strategies are already identified. They start with high-quality services in the early years. Despite important initiatives such as free childcare for disadvantaged two-year-olds, more than a third of children from poorer families start school behind their peers, with communication a key area of concern.

In school, despite huge progress by successive governments, there remain pockets of underachievement often in the poorest or isolated communities. Initiatives such as the National Teaching Service must be reinvigorated with the ambition of placing high-quality teachers in poor performing schools. Evidence shows that well-qualified, experienced teachers are the key ingredient to boosting educational attainment in the classroom. The £2.5bn pupil premium must be protected. Opportunity areas, which build on the success of the London challenge, have the potential to raise standards in areas which need help.

Beyond school, we know that high-quality technical education combined with English and maths to 18 is key.

We must be ambitious in education policy, relentlessly focusing on opportunity and tackling disadvantage for all

Underpinning all this must be adequate resources for all schools so headteachers can focus on providing an excellent education. Analysis published last week by the Education Policy Institute and others shows the funding pressures schools are facing, on top of changes introduced by a new national funding formula, suggesting head teachers will have their work cut out.

We must be ambitious in education policy, relentlessly focusing on opportunity and tackling disadvantage for all. That’s why it is disappointing that the government is focused so heavily on expanding selection. While there are positive moves in other areas, such as the new T-levels and opportunity areas, all this good work will be squeezed out by an endless debate about more selection.

All the evidence is clear that grammar schools damage social mobility. While they can boost attainment for the already gifted, they do nothing for the majority of children who do not attend them. Indeed, in highly selective areas children not in grammars do worse than their peers in non-selective areas.

Having the brightest children in comprehensive schools helps raise standards for all, increasing aspiration and intellectual capital in a school. This isn’t a zero-sum game. As Sir Michael Wilshaw has said, he delivered an excellent education for his pupils through the comprehensive system precisely because the school was mixed ability.

Those championing selection as the silver bullet for tackling social mobility, or as the panacea for creating good new school places, are misguided.

In a time when resources are so limited and many other educational reforms are still in their infancy or yet to be proved – from university technical colleges and new T-levels to the expansion of free childcare and hundreds of new free schools – now is not the time for more division or political ideology in education.

Times have moved on. Expanding selection isn’t part of the answer to tackling social mobility.

Ministers talk about creating a so-called meritocracy, with opportunity in the hands of individuals based on their ability and talent alone. True social mobility is about giving people chances and choices so that they can overcome the challenges they face.

Our economy and country is changing fast. We must rise to the challenge with a new national mission to boost education and social mobility for all. That’s why we are putting aside what we disagree on, to come together and to build a cross-party consensus in favour of what works for our children – not what sounds good to politicians.

Nicky Morgan, former education secretary, is Conservative MP for Loughborough; Lucy Powell is Labour MP for Manchester Central; Nick Clegg, former Liberal Democrat leader, is MP for Sheffield Hallam