EU referendum: Vote Leave says Brexit would lead to higher wages and cheaper energy billsIBTimes UK

Leaving the European Union would be "a threat to the wellbeing of the UK", the chief of the Organisation for Economic Cooperation and Development (OECD) has said on Wednesday (1 June 2016).

Speaking in Paris, Angel Gurria said that a vote to leave the 28-country bloc would financially penalise the UK and could wipe a month's wages off Briton's potential incomes.

Brexit, Gurria said, is: "a threat, but mostly it's a threat to the wellbeing of the UK. It's like a tax", although one "for which you get nothing in return".

In its semi-annual financial outlook, the OECD added that the uncertainty surrounding the outcome of the referendum "has led to a significant slowdown in economic activity". The OECD also slashed its forecast for UK growth for 2016 to 1.7% from the 2.2% figure it predicted in February, indicating the economic recovery in the UK remained far from impressive.

"Eight years after the financial crisis, the recovery remains disappointingly weak," it said in a statement. "The forthcoming UK referendum on EU membership has already raised uncertainty, and an exit would depress growth in Europe and elsewhere substantially."

The OECD added leaving the EU would also have broader implications as it would trigger turmoil in financial markets across the world.

"A decision to exit would result in considerable additional volatility in financial markets and an extended period of uncertainty about future policy developments, with substantial negative consequences for the United Kingdom, the European Union and the rest of the world," it said.

The warning to British voters came as the OECD warned the global economy remains frail and would only improve marginally in 2017 after failing to pick up this year. According to OECD estimates, the world economy will expand 3% this year, matching the rate of expansion recorded in 2015, and will only improve "a little" in the following 12 months.

"Overall a rather mediocre, a rather dismal outlook," Gurria said. "Trade is growing at 2% to 3%, it should be growing at 7%."