LONDON (Reuters) - Tunisia, which has lurched into its worst political crisis since the Arab Spring protests in 2011, needs to save its foreign exchange reserves and secure a deal with the International Monetary Fund (IMF) to avoid another sovereign rating downgrade, credit rating agency Fitch said on Monday. The North African country’s economic difficulties have already seen its rating chopped once by Fitch this month, but the weekend’s move by President Kais Saied to oust the government with help from the army has thrust it into full-blown turmoil. Fitch’s primary sovereign analyst Cedric Berry laid out what could trigger another downgrade from its current B- grade into the CCC bracket, which is the last stop before default. “It would be a mix of things,” Berry told Reuters. “One is the external finances, and if we see the FX reserves dropping rapidly in the context of a diminishing prospect of an IMF deal”. An IMF spokesperson told Reuters that it was closely monitoring the situation in Tunisia but stood ready to continue its support. Failure to agree a deal, which had been expected to be worth around $4 billion, would keep heavy reliance on domestic banks to provide funding with the country now unlikely to be able to borrow in international bond markets as planned, Fitch said. The country, which was the only democracy to emerge from the Arab Spring protests a decade ago, faces public debt payments worth around 4% of GDP per year on average over the next two years, the rating firm estimates. Its current account deficits are projected to average around 8% of GDP over the same period, 17% of GDP is spent on public sector wages, while foreign-exchange reserves have dropped by around a billion dollars since the start of the year to $8.9 billion. When asked whether Fitch was prepared to wait till the end of the year before it makes a decision on rating, Berry said: “It is very unclear - the negative outlook is based on factors that don’t follow a clean timeline.” (Graphic: Tunisia"s fast rising debt level, )