London Stock Exchange
Stocks, pound sterling registered sharp gains as concerns over a possible British exit recede. Getty Images

UK share indices and the pound sterling registered sharp gains on Monday (20 June), as the latest round of opinion polling eased concerns over a possible British exit from the European Union.

At 1:36pm BST, the FTSE 100 was up 3.38% or 203.47 points at 6,224.56, while the FTSE 250 was up 3.40% or 558.83 points at 16,980.87, as a fresh batch of polls suggested the result is in the balance with the remain camp having a marginally stronger hand.

On Saturday, pollsters Opinium and YouGov suggested the leave and remain campaigns were neck and neck, while Survation had remain up by three points. A subsequent poll for the Sunday Times by YouGov also had the remain campaign by one point up.

Laith Khalaf, senior analyst at Hargreaves Lansdown, said the market was gearing up for more of the same before the result of the 23 June referendum is known.

"Waves from the Brexit vote are buffeting the UK stock market, tossing it up and down as the opinion polls shift this way and that. Until the vote is over we can expect more price swings, as markets struggle to price in a unique event that carries with it such a high degree of uncertainty."

Separately, an IBTimes UK report revealed money managers were advising their clients to invest in UK equities should a Brexit take place.

So far, housebuilders and financial services shares have been the beneficiaries of the latest rally, as the pound also registered appreciable gains in Asian and European foreign exchange trading. At 2pm BST, one pound exchanged at $1.4641 and €1.2907, up 1.96% and 1.48% respectively, having registered gains against all major currency crosses.

Kit Juckes, head of foreign exchange at Societe Generale, said Asian markets are in 'risk-on' mode as traders bet that the UK will remain in the EU.

"The pound is leading the foreign exchange charge with the yen at the bottom of the pile. The only currency other than the yen to fall against the dollar this morning is the Indian Rupee, hurt a bit by the confirmation that Raghuram Rajan will return to academia when his term as RBI Governor ends in September."

Juckes added that the currencies market will gyrate some more in the next few days as any shift in that UK opinion polls is likely to trigger an "exaggerated reaction", not just for the pound but for wider risk sentiment.