David Cameron: 'Tax avoidance must be tackled'

UK Prime Minister David Cameron has said that countries must work together to clamp down on tax avoidance.

Speaking at the World Economic Forum in Davos, Mr Cameron said that the issue was one of the UK's main priorities for its presidency of the G8 group of richest nations in 2013.

"There are some forms of tax avoidance that have become so aggressive" that it is time for international co-operation to make sure that global companies pay their fair share of tax, he said.

It comes a day after he called for negotiations on the UK's place in the European Union, followed by a referendum.