There is no doubt that they are powerful and emerging economies which are increasingly important on the world stage, to the extent of eclipsing some of the current Group of Eight members.

"When we were deciding on who would be invited to participate in the summit, the Russian president's position was that it was pointless to discuss energy security without India and China," said Igor Shuvalov, a top aide to President Vladimir Putin, ahead of the Saint Petersburg meeting.

"They exercise a great influence on price growth, are leading consumers of energy resources, and have developing economies," Shuvalov explained.

As a result, the presidents of China, India, Brazil, South Africa and Mexico are to meet three times on July 17 with G8 leaders, essentially to discuss energy supply, distribution and conservation issues which Moscow set as the summit priority.

Another reason Shuvalov gave for their presence was that "these countries are ready to develop nuclear power on their territories, which is a priority for the Russian presidency of the Group of Eight."

Russian leaders are not alone in pushing for greater participation by emerging countries.