Mr Chavez's ambitions to join Mercosur (the regional integration scheme founded by Argentina, Brazil, Paraguay and Uruguay) were long blocked by the Paraguayan senate.

BBC: Analysis: How Hugo Chavez changed Venezuela

This was followed by Alba, a regional integration scheme that would grow to include Cuba, Bolivia, Ecuador, Honduras (until 2009) and Nicaragua, as well as a few small independent Caribbean states.

BBC: Analysis: How Hugo Chavez changed Venezuela

"If a scheme were to remove integration then generally employers or employees would have to pay more into the scheme, " said Mr Astley.

BBC: Fight to end pension 'clawback'