One week to EU vote, investors nervous as Brexit looms

The Financial Times warned Thursday against Britain quitting the EU amid nervousness on the financial markets, as a new poll showed a big swing towards the "Leave" camp with one week to go.

The Ipsos Mori survey showed 53 percent in favour of a Brexit compared to 47 percent who wanted to stay in the European Union -- a marked change from last month when the "Remain" camp was leading by 57 percent to 43 percent, excluding undecideds.

It is the third telephone poll in less than a week to give the "Leave" camp the advantage ahead of the June 23 referendum that is weighing on stock markets around the world and sending the pound tumbling.

Asian and European markets sank on Thursday following a warning by US Federal Reserve boss Janet Yellen that a Brexit could have consequences for global financial markets and the US economic outlook.

London`s FTSE 100 share index was down 0.5 percent to 5,935 points at 1035 GMT, while the pound reached a new two-month low against the euro.

"City watchers are beginning to take the threat seriously and start to price in the possibility of a Brexit," said Joe Rundle, head of trading at ETX Capital.

Overnight, leading business newspaper the Financial Times endorsed the "Remain" camp, saying Britain had benefited from its 43-year membership of the European fold and leaving would "seriously damage" the economy.

It said a choice for "Leave" would favour "a pinched nationalism" and "marginalisation", adding: "A vote to withdraw would be irrevocable, a grievous blow to the post-1945 liberal world order."

`Startling dishonesty`

Mark Carney, the governor of the Bank of England, is among a raft of economists and senior figures from international organisations such as the IMF to have warned of the economic risks of a Brexit.

But in a letter to The Daily Telegraph newspaper, two former British finance ministers and two former Conservative Party leaders accused Carney of peddling "scare stories".

"There has been startling dishonesty in the economic debate, with a woeful failure on the part of the Bank of England, the Treasury, and other official sources to present a fair and balanced analysis," wrote Nigel Lawson, Norman Lamont, Michael Howard and Iain Duncan Smith.

"They have been peddling phoney forecasts and scare stories to back up the attempts of (Prime Minister) David Cameron and (finance minister) George Osborne to frighten the electorate into voting Remain."

The BBC meanwhile published an exchange of letters between a senior Vote Leave campaigner and Carney, in which the governor was warned to stay out of the EU debate -- and refused, saying Britain`s central bank had a "duty" to inform the public.

Carney and Osborne will both speak at the City of London financial hub`s annual gathering on Thursday evening.

In an article in The Times newspaper, the prime minister accused those backing "Leave" of "playing fast and loose" with readers` financial future "for their political ends".

This will be viewed as a veiled reference to leading Brexit campaigner Boris Johnson, the former mayor of London widely tipped as a likely successor to Cameron.

Elsewhere, three leading companies threatened legal action against Vote Leave for using their logos without permission, implying they backed a Brexit when they did not.

"We believe our companies have been used for propaganda purposes," said the letter from Airbus Group UK president Paul Kahn, Unilever chief executive Paul Polman and Mark Elborne, chief executive of GE UK and Ireland.

Guarantee on Turkey

While the "Remain" campaign has been focusing on the economy, their rivals have made immigration a key issue for them -- particularly the prospect of Turkey joining the EU.

Cameron has said Turkey will not join the bloc until the year 3000, but Johnson on Thursday demanded a guarantee that Britain would block Turkish membership and the extension of visa-free travel throughout the EU.

Without it, "the public will draw the reasonable conclusion that the only way to avoid having common borders with Turkey is to Vote Leave," he wrote to the premier in a letter signed by other Brexit campaigners.