The chance of a global trade deal being clinched before President George W. Bush leaves the White House shrank dramatically yesterday 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.