Mexican migrant labourers sent home $16.6bn in remittances last year a 24 per cent increase on 2003 thanks largely to the improving US economy and reductions in remittance charges.

The news on Monday came the same day that Standard & Poor's, the ratings agency, upgraded Mexico's sovereign debt rating, and as Mexico City's stock exchange hit a new record. The peso also strengthened against the dollar, while Mexico's central bank announced provisional figures that gross domestic product had risen by 4 per cent .