The chance of a global trade deal being clinched before President George W. Bush leaves the White House shrank dramatically on Thursday with talks between core negotiating partners collapsing again in division and acrimony.

In a near-exact repeat of events last summer, talks in Potsdam, Germany, between the four partners at the centre of the so-called Doha round of negotiations – the EU, US, Brazil and India – broke up with sides still far apart on cutting agricultural subsidies and goods tariffs.