The director-general of Unesco has urged UK businesses to help tackle the world's "learning crisis".

Irina Bokova, speaking at a Business Backs Education summit at City Hall in London, said firms had a "major stake in education" and hold the "the potential to help address some of the global learning crisis".

Bokova's comments coincided with the launch of research from Business Backs Education which found that top UK companies only spend a fraction of their corporate social responsibility budget on education.

The Business Backs Education campaign challenges business to commit 20% of their global CSR spend on education by 2020, to bring business in line with government and NGO education spending targets.

The report argued that If UK companies committed 20% of their CSR budgets towards education initiatives, the total education CSR spending would more than double to $650m.

The group said the effect of this in human terms would be significant, enabling 750,000 additional children per year worldwide to study in primary school.