Today’s G20 summit is Barack Obama’s first big international test as US President.But it is also a huge test for British Prime Minister Gordon Brown, who is hosting the gathering of the world’s most influential leaders on his home turf in London. The G20 hope that the estimated 1.5 trillion euros governments are pumping into the global economy by way of tax cuts, building projects and green investments will limit the depth and duration of the recession and create around 20 million jobs. But Germany and France have already joined forces to demand that promises of tough financial market regulation are also delivered on. As the dignitaries convened at Buckingham Palace for a dinner with the Queen last night, officials were hammering out the details of what will be announced today. They are also hoping to drum up at least 377 billion euros the IMF can use to bail out economies which are heading for trouble.