Between 20% and 50% of all timber sold worldwide has been illegally sourced according to Projects Abroad – the world's largest volunteering organisation.

"For many years the volume of timber taken from rainforests by far out-strips the rate of planting," said Dr Peter Slowe - managing director of the UK-based Projects Abroad and a former economic policy advisor to Tony Blair who sits on Labour's Finance and Industry Group.

"When this is allied to illegal logging, worldwide deforestation will reach crisis point – beyond which restoration will be extremely difficult – at some time this year," he said.

Projects Abroad owns 476 hectares of Amazon rainforest which it runs as a reforestation and educational project. Many thousands of volunteers, of all academic levels, have worked at the site which is at Taricaya in Peru.

"The average rotation of planting timber is only between 30 and 40 years which is not long enough for the trees to produce the volume of wood necessary to satisfy worldwide requirements. This inevitably leads to continuing illegal ingress into the primary forest," said Dr Slowe.

'Chainsaw' – a joint project between the World Bank and Interpol – reported last year that an area of the world's rainforest the size of Austria was illegally felled every twelve months.

"The only way forward is through much stiffer timber security and for affluent western countries to pay emerging nations to preserve their forests - probably under a scheme called Reducing Emissions from Deforestation and forest Degradation (REDD)," said Dr Slowe.

Deforestation accounts for very nearly a quarter of all the greenhouse gasses created by human activity each year.

Projects Abroad has sent more than 41,000 volunteers to 27 different countries since its inception in 1992. Last year, they sent around 8,000 volunteers on projects and are predicting an increase of at least 10% this year.

Volunteers visiting Project Abroad's Taricaya project are given the opportunity to take part in important research work and biodiversity studies into all types of flora and fauna. Taricaya has South America's highest canopy walkway, a freshwater turtle project, and a pilot farm.