Schooling in Poland

Highlighting the Coalition's reforms in a speech in London yesterday, Mrs Morgan said: "As exam results in England soared ever higher, our international performance was stagnating, with other countries overtaking us in rankings like the PISA survey.

"We knew we needed to make urgent changes and looked to the world’s leading education systems for inspiration. We saw that they shared some key features: high levels of autonomy, accountability and aspiration as well as a strong focus on teacher quality.

"We saw that the results of countries like Germany and Poland had improved massively following moves to ensure that all their pupils studied core academic subjects, regardless of whether they went on to an academic or vocational path."

Poland has overhauled its education system over the past decade and gone from being below average in the OECD group of economies to being among the top 10 nations for reading and science, and top 15 for maths. Pupils attain higher scores on international tests than Britain in both reading and maths.

Under the reforms in Poland, pupils spend more time studying core subjects and vocational study has been delayed until they are 16.

The Coalition echoed the changes in new national curriculum announced last year which has a greater focus on core subjects and more exacting standards.

One education source said: "Polish parents who come to the UK say they cannot believe how easy the national curriculum is compared to what they are used to."

According to the OECD, the performance of Britain's schools failed to improve significantly between 2000 and 2012.

The report found that overall UK is ranked just 26th out of 63 nations for its performance in maths as it lags behind countries in the Far East.

Andreas Schleicer, the OECD director of education and skills, said: "The UK has pretty much been flat in terms of learning outcomes at least until 2012, despite a very significant increase in spending.

"Spending on reducing class sizes is not a very promising way to invest on better outcomes. The best education systems have put their money squarely on the quality of teaching. "

He said that the UK should be doing much more to check what difference education reforms make to children's lives.

Around the world, trillions of dollars are spent on education policies, but just one in 10 are actually evaluated, according to new research by the Organisation for Economic Co-operation and Development (OECD).

The OECD's research also warns that the UK has some policies such as grouping pupils by ability in class, and giving families choice over schools, that could "hinder equity" – meaning they may not help to create an equal school system for all pupils.