Asset manager BlackRock has warned that the British economy will suffer if the UK leaves the EU - with its equity markets, property market and currency all taking a hit.

The client report also says that David Cameron is likely to lose control of the Conservative party no matter what the result of the June 23rd vote is.

He has already ruled out another term, the vote is likely to lead to factions being formed within the party, with potential future leaders using the vote as a platform to establish themselves.

However, those in the 'out' camp are likely to point to the fact that the report was authored by Rupert Harrison who is a former chief of staff to Chancellor of the Exchequer, George Osborne.

Mr Osburn and the rest of the Conservative Party leadership have been accused of orchestrating a campaign to scare the British public into voting to remain part of Europe.

"We see an EU exit leading to lower UK growth and investment and potentially higher unemployment and inflation," Philipp Hildebrand, BlackRock’s vice-chairman said.

"Our bottom line is that a Brexit offers a lot of risk with little obvious reward," he continued.

He said the split allegiances in the Conservative Party "spell trouble for post-referendum unity regardless of the vote’s outcome and would make it harder to pass controversial legislation."

The firm says that British equities and the sterling would suffer and that the impact of a breakaway would be long-lasting.