Like measuring water by the handful, calculating the success of the education system at a time of rampant grade inflation is an impossible task. If exam results go up every year how can we know if are our children are actually getting a better education or if exams are just getting easier?

Part of the answer is international comparisons – which is why the OECD PISA rankings published today do actually matter. The last time they were published, in 2009, they showed that as a country we slipped to 25th in reading, 28th in maths and 16th in science. Yet at the same time domestic UK exam results were getting better. If you think that doesn’t add up, that’s because it doesn’t.

In their haste to provide positive headlines and tokens of success, Labour left behind the one thing that actually mattered – giving children a decent education. By looking at standardised international indicators we can get a sense of what was actually going on. Of course they are not perfect – far from it. But the OECD commands independence from the UK’s education establishment, and when impartial advisors speak we must listen.

The picture painted by today’s PISA results was one of stagnation. These are the results of teenagers who took the tests in 2012 – the children of Labour’s education system. They are in danger of becoming a lost generation, entering the job market without the skills needed to succeed.

No one knows more about the economic cost of a failing system as the OECD themselves. Andreas Schleicher the OECD’s education chief, and the man behind today’s PISA results, has written that problems with the UK’s schools cost us £4.5 trillion in lost economic output over a lifetime, something he calls ‘the equivalent of a permanent recession’.

That is what happens when you think that second best is good enough. In the globalised world businesses can settle wherever they choose. Our future prosperity depends on them choosing to settle here. Whether that means turning our network of embassies into showrooms for Britain’s best businesses, sending our Prime Minister on trade visits to China, or reforming our school system so that it can provide the skills our children need – we will do what it takes for Britain to succeed in the global race.

The winners in the latest PISA tests are countries that listened to international warnings and followed the path of reform. That means recruiting better teachers and giving heads autonomy over bureaucracy.

These are the principles which have inspired our reforms since 2010. Giving more than 3,400 schools the freedoms that come with academy status, allowing head teachers to reward excellence in their staff through higher pay, and putting rigour back into the national curriculum – these are the instruments of our long term plan for education.

At the same time we’ve faced the opposition of Labour and the teaching unions, who are committed to maintaining the failure they created. The lesson of Labour’s stagnation is that we cannot be content, but instead must aim higher. That’s why we will take a zero-tolerance approach to failing schools, make it easier to get bad teachers out of the classroom and increase the pay and freedom of the growing army of good teachers. All these measures are opposed by the Left.

Labour have not learnt the lesson of these international comparisons, but those of us who care about children reaching their full potential must. It is only by learning from other nations and confronting failure at home that we can promise our young people a brighter future.

Chris Skidmore is THE Conservative MP for Kingswood and a member of the Education Select Committee

Tags: Education, Education reform, Michael Gove, PISA, Schools, UK politics