Using research by the Australian National University (ANU) and Kings College, London, the charity says it will be the first time poverty has risen globally in 30 years.

"The economic crisis is potentially going to be even more severe than the health crisis," said the report.

It estimates a 400-600 million rise in poverty numbers globally.

The findings come ahead of key meetings of the World Bank, International Monetary Fund, and G20 finance ministers next week.

The report says the potential impact of the virus poses a real challenge to the United Nations Sustainable Development Goal of ending poverty by 2030.

"Our findings point towards the importance of a dramatic expansion of social safety nets in developing countries as soon as possible and - more broadly - much greater attention to the impact of Covid in developing countries and what the international community can do to help," said Professor Andy Sumner of King's College London.

By the time the pandemic is over half of the world's population of 7.8 billion people could be living in poverty. About 40% of the new poor could be concentrated in East Asia and the Pacific, with about one third in both Sub-Saharan Africa and South Asia.

Danny Sriskandarajah, Oxfam GB's chief executive, said: "For billions of workers in poor countries who were already scraping by, there are no safety nets such as sick pay or government assistance.

"Next week's World Bank and G20 meetings are an important opportunity for world leaders to collaborate on a joint economic rescue package to protect the most vulnerable people."

Earlier this week, more than 100 global organisations called for debt payments to be waived this year for developing countries, which would free up $25bn (£20bn) in cash to support their economies.