The International Monetary Fund (IMF) last night called for a "policy game changer" in the eurozone to arrest the spread of the debt crisis it says is engulfing the entire currency bloc and its smaller neighbours, The Telegraph said.

An IMF spillover report that looks at how the economic policies of the so-called systemic five economies – the United States, China, eurozone, Japan and the United Kingdom – affect each other and the rest of the world, said the eurozone crisis was by far the biggest concern on policymakers' minds.

The IMF said it had consulted 35 countries for the report, including emerging economies such as Brazil, Czech Republic, India, South Africa, Turkey, Russia, South Korea, Poland, Mexico and Saudi Arabia.

"Despite progress in the face of constraints, the sense is that not enough has been done to stop the spread of stresses and attenuate fiscal growth-banking feedback loops," the IMF said of the eurozone's policy actions so far.

In a worst-case scenario simulated by the IMF, it found that eurozone output could be cut by five percentage points if policymakers did not act and the eurozone crisis worsened.

If the crisis intensified, the IMF estimated that the impact to the world's poorest countries would be somewhere between mild to severe, and could push up their external financing needs by some $27bn by the end of 2013.

But the IMF said the eurozone was not the only global worry. Weighing possible spillovers elsewhere, the IMF also said the US must remove the threat of a so-called "fiscal cliff" in 2013, with $4tr of expiring tax cuts and automatic government spending reductions next year, and not enough fiscal adjustments over the medium term.

Most analysts believe that Congress will not act until after the congressional and presidential elections in November.

Of China, the IMF said there was a concern that slower investment, while necessary to rebalance demand to consumption, would hit trade partners and world prices. A one percentage point cut in Chinese investment growth would have a large impact on its Asian suppliers, while effects on Japan and Germany would also not be trivial, it added.

High public debt in Japan makes it vulnerable to an abrupt shift in market sentiments, while the UK should take further steps to fortify its financial system and underpin confidence in banks, the IMF said.

Ranjit Teja, the report's lead economist, said emerging economies had complained that easy monetary policy in the US, Europe and Japan had created a surge in capital inflows, higher commodity prices and raised the risk of asset bubbles.