Brazilian and Argentine diplomats can be guaranteed to downplay the significance of President Hugo Chávez’s absence from this week’s summit meeting of Mercosur in Asunción, Paraguay’s capital.

The trip that Mr Chávez will make instead to Russia, Iran and Belarus is clearly important. But it is hard to avoid the impression that Mr Chávez’s no-show is more than just the result of an overloaded diary. After all this will be the first time since Venezuela joined Mercosur in December 2005 that Mr Chávez will have missed a summit and a chance to press his case for a “profound reform” of the trade block.