The Prime Minister arrives at the G20 summit in Mexico this lunchtime as world leaders assess the fallout from the elections in Greece.
The two day summit in the resort of Los Cabos will bring together the leaders of the 19 biggest global economies plus the European Union.
The summit should be less frenetic than it might have been had there been a different result in Greece yesterday.
The G20 leaders represent two thirds of the global population and 90% of the world's GDP.
Before he arrives for the opening of the G20, David Cameron will give a speech to the B20 - a business summit which is held alongside the political one.
Mr Cameron says that 'delays' would be "dangerous" in Greece and that the government needs to "act swiftly".
He will tell delegates that world leaders need to tackle what he calls the "five greatest threats facing the global economy".
Among the five threats he cites are:
- The eurozone crisis
- Sovereign debt
- Failure to regulate the banking system
He will again urge the 17 members of the eurozone to do whatever is necessary to save the single currency. He is expected to say: "There are a set of things the eurozone countries need to do. And its up to eurozone countries whether they are prepared to make the sacrifices these entail."
That is another warning to the German Chancellor Angela Merkel that she must make political 'sacrifices' and use her economy to stand behind the weaker Euro countries - however unpopular that might be at home.
The German leader and the new French President Francois Hollande are expected to depart for the G20 as late as possible so that they can assess the outcome of the Greek elections first.
Chancellor Merkel will come under intense pressure at this Mexican resort to back down on her repeated refusal to support Eurobonds - in order to share the debt of the eurozone countries across all its members.
President Obama blames the eurozone crisis for stunting economic growth worldwide and last night the White House said of the Greek result: "We hope this election will lead quickly to the formation of a new government that can make timely progress on the economic challenges facing the Greek people."
The sun will be shining on the southern tip of the Baja California peninsula where this summit is taking place. But the financial storm clouds will be chasing in from across the Atlantic.
And they all know the Greek result may not look quite so shiny after a few short turbulent weeks.