Stockmarkets seemed to shrug off forecasts by the IMF yesterday that global economic growth would fall by another notch or two to 3.2% this year and continued their recent rally on the back of higher oil prices and strong export data from China.

In London, the FT100 share index hit a three-month high of 6,200 in response to Russia’s latest oil production freeze deal with Saudi Arabia which caused the price of Brent Crude to jump 4% to $43, its highest level this year.

China reported stronger than expected trade data ahead of Friday’s expected publication of first-quarter economic growth.

Exports jumped by close to 19% in local currency terms compared to the same month last year after declines in both February and January.

Imports also stabilised, slipping by just under 2% compared with an 8% fall in February.

The IMF warned that UK and EU growth are likely to be affected by the outcome of the Brexit referendum.

Its chief economist Maurice Obstfeld said: "The planned June referendum ... has already created uncertainty for investors. A Brexit could do severe regional and global damage by disrupting established trading relationships".

It is perhaps the gravest statement on a potential Brexit released from a major international body.

Responding to the IMF report, the British Chancellor of the Exchequer George Osborne commented:

"Well today we have a stark warning from the IMF. For the first time they're saying that the threat of Britain leaving EU is having an impact on our economy and they cut our growth forecast as a result.

"They say were we actually to leave the EU there would be a short-term impact on stability and a long-term cost to the economy."