Finance ministers and central bank governors are today expected to give Rodrigo Rato, managing director of the International Monetary Fund (IMF), the green light to draft a plan to give emerging market economies a greater stake in the fund.

China, South Korea, Turkey and Mexico are expected to be the biggest immediate winners from the shake-up. Policymakers hope it will increase the IMF's legitimacy and bind rising economic powers more tightly into the multilateral financial system.

But the meeting of the IMF's ultimate governing body, the International Monetary and Financial Committee (IMFC), in Washington today is set to see tough bargaining over the wording of the mandate.

The US is determined that an initial step this year should lead to a root-and-branch reform of the way the IMF's shareholdings or "quotas" are allocated. Smaller European countries and some other nations that benefit from the current arrangements are fighting against this.

The IMFC is also expected to back Mr Rato's plan to develop a programme of "multilateral surveillance" in which the IMF would examine the way policies in countries such as the US and China affect one another and the global financial system.

The US hopes the new process will encourage the IMF to put more pressure on China and other Asian countries to allow their currencies to appreciate.

There is consensus that China, South Korea, Turkey and Mexico should be granted an "ad hoc" quota increase to raise their shareholding at the next IMFC meeting in Singapore in September.