Prime Minister David Cameron has arrived in Mexico for a G20 summit of the world's leading economies which will be dominated by the crisis in the eurozone and the fallout from the Greek elections.
Before leaving London, Mr Cameron held a conference call with the leaders of Germany, France, Italy and Spain as well as the presidents of the European Commission and European Council.
It is understood the leaders were encouraged by the results of the ballot, which saw the centre-right New Democracy party outpoll the far-left Syriza in an outcome which makes a Greek departure from the euro less likely.
But there is now a sense of urgency about New Democracy - which is signed up to the austerity programme demanded in return for Greece's multibillion-euro bailout - forming a coalition government in Athens.
Mr Cameron is expected to use a speech later to step up pressure on the 17 eurozone countries - and particularly Germany and the European Central Bank - to take decisive action to address the fundamental problems behind the crisis in the single currency.
Europe's leaders must be ready to take tough political decisions or face the threat of either "perpetual stagnation" or a hugely damaging break-up of the single currency, he will warn.
He has taken a 25-strong business delegation with him to Mexico in a sign that he wants to build trade links with emerging economies around the world to make up for continuing weak demand from traditional markets for British exports in Europe.
Speaking to a business audience in the Pacific resort town of Los Cabos, the Prime Minister will put the crisis in the euro area at the top of a list of "five big threats to the global economy".
He will urge fellow G20 leaders to take "bold steps" to restore growth, and will warn against "backsliding" on trade protectionism and reforms to financial regulation. A failure to follow through on pledges made at previous summits to reform the banks would leave the world exposed to a repeat of the 2008 financial crash, he will warn.
No corner of the world is safe from the five threats of the eurozone instability, sovereign debt, low growth, protectionism and failure to regulate the banks, the PM will say. "These five threats are very real. And let's be clear - in a global economy, they threaten us all."