EU Commission Vice President Kristalina Georgieva has said she is leaving the EU's executive body the take up a senior position at the World Bank.

The development is due to take effect as of January 02, 2017, Georgieva has said in a statement.

Her new appointment means Bulgaria will have to propose a successor.

Georgieva is due to become Chief Executive Officer at the International Bank for Reconstruction and Development (IBRD) / International Development Association (IDA) at the World Bank Group.

"When I arrived at the European Commission in 2010 from the World Bank I was leaving behind not just a job and an organisation that I loved, but a sector too: the world of Global Development," the Commission's Vice President in charge of budget and human resources says.  

"I thought long and hard about my decision to accept the post of Chief Executive Officer IBRD/IDA at the World Bank Group. But finally I could not turn down the opportunity to return to a field which continues to fill me with passion for the work and the possibilities it brings for making an enduring difference to Europe and the rest of the world."

However, Politico quotes a commission source close to her claiming her resignation was caused by frustration with the way Brussels handles "such challenges as migration, Brexit and senior appointments." 

Her particular objections were to the working methods of Marin Selmayr, Juncker's Chief of Staff whom she reportedly considers to be a "poisonous" influence on the Commission. 

Georgieva came in as an eleventh-hour replacement proposed by Bulgaria in 2010, when the EU Commission candidate of Bulgaria, Rumyana Zheleva, fared disastrously at a Brussels hearing. She was then assigned the humanitarian affairs portfolio. She was handed a vice presidential office in Jean-Claude Juncker's commission college that was formed in 2014. 

She ran for UN Secretary General earlier this year as Bulgaria's official nomination. According to Politico, her failed bid also played a part.