China will push the Brics bloc of emerging markets to become a full-scale rival to the G7 this week, as leaders from across the developing world gather to debate the forum’s biggest expansion in more than a decade.

South Africa’s President Cyril Ramaphosa has invited more than 60 heads of state and government to a summit in Johannesburg from Wednesday when several countries could be invited to join the bloc of Brazil, Russia, India, China and South Africa, said several officials familiar with talks.

But in the run-up to the summit New Delhi has clashed with Beijing over the expansion. Tensions are mounting over whether the Brics should be a non-aligned club for the economic interests of developing countries, or a political force that openly challenges the west, said people briefed on India and China’s positions. South African officials said 23 countries are interested in joining.