Theresa May is "hanging on by a thread" and businesses should prepare for a government led by Jeremy Corbyn, the world's largest financial exchange operator has warned.

A paper issued by CME Group entitled "What to Expect from a Prime Minister Corbyn" was sent to investors and business leaders last month, and included a prediction that a Labour government would lead to a possible "nightmare scenario for the pound".

It is one of a series of cases of major organisations preparing for Mr Corbyn coming to power in the weeks Mrs May's minority government has been rocked by a series of damaging rows and Cabinet resignations, as well as growing uncertainty over negotiations with Brussels over Britain's departure from the European Union.

The paper issued by CME, a US-based financial and commodity derivative giant, is one of several issued by respected firms within the last two months advising on how Mr Corbyn's policies could affect businesses and investors.

Separately the Telegraph understands that a series of FTSE 100 companies are privately "contingency planning" for "socialist" policies that would accompany a government led by Mr Corbyn.

Business leaders have also quietly been holding talks with Labour frontbenchers, including Sir Keir Starmer, the shadow Brexit secretary.