The International Monetary Fund (IMF) has warned it may not have enough money to bail out larger eurozone countries if the debt crisis were to spread.IMF chief Christine Lagarde says the global lender can meet its current obligations but this could change if the crisis worsens.Publicly, world leaders have said there is \"no plan\" for a Greek default.But reports suggest leaders are working on a plan to allow Greece to default on its debts and remain in the euro.It is believed that policymakers feel they need to concentrate on recapitalising banks and boosting the funds of the European Financial Stability Facility (EFSF).BBC business reporter Joe Lynam says that the plan to increase the EFSF\'s financial firepower could see the money available to bail out EU banks and member states rise from 440bn euros ($596bn; £385bn) to about 2 trillion euros.He added that the plan could also enable the European Central Bank to buy more Italian and Spanish bonds to prevent those two countries needing a full bailout.Ms Lagarde will meet Greek Finance Minister Evangelos Venizelos later.Greece\'s minister for international economic relations, Constantine Papadopoulos, said leaving the euro would be \"catastrophic\" for Greece.\"I personally think [leaving the eurozone] would take us back to the 1960s or 1970s,\" he told the BBC\'s Andrew Marr programme.He later clarified that he was not referring to the political situation at the time, when the military took power in a coup, but the standards of living and the structure of the economy.This week will see EU and IMF officials return to Athens to monitor the country\'s progress on its deficit reduction plans.Greece is still receiving money from an initial rescue, agreed in May last year, although it will not receive the next tranche if nspectors rule that it is not keeping up with its spending cut targets.Analysts say this is a real possibility.Without this month\'s loan, Greece will not be able to meet its debt payments by the middle of next month.A second EU-IMF bailout was agreed for Greece in July of this year but that still has to be ratified by the parliaments of a number of eurozone member states. From / BBC