Sri Lanka's International Monetary Fund bailout plan could be a turning point in its worst economic crisis, but far-from-stable politics and a need to get debt relief from competing powers China, India and Japan means some of the hardest work is still to come.

Sri Lankan President Ranil Wickremesinghe knows a lot of circles will need to be squared for the IMF's $2.9 billion lifeline to become a reality.

Spending cuts, tax hikes and debt write-downs are a common formula for bankrupt countries, but crisis veterans say there are some uniquely difficult elements here.