FTSE hits two-month high as Britain votes on EU membership

* FTSE 100 index up 1.2 pct at close, a 2-month high

* Set for biggest weekly gain since 2011

* Miners track metals prices higher

* Tesco (Xetra: 852647 - news) advances after sales update (Adds detail, updates prices)

By Kit Rees and Atul Prakash

LONDON, June 23 (Reuters) - Britain's top share index rose to a two-month high on Thursday as Britons voted on membership of the European Union after opinion polls showed support for the "Remain" camp rising.

Two opinion polls published late on Wednesday showed signs of a last-minute rise in support for staying in the EU. Investors fear Brexit would damage the economy in Britain and beyond.

"Overnight polls still suggest the result could be very close, although a late tilt towards Remain has helped bolster bullish sentiment on the hope the status quo is maintained and an uncertain outlook will not prevail," said Mike van Dulken and Augustin Eden at Accendo Markets.

The blue-chip FTSE 100 index was up 1.2 percent at 6,338.10 points at its close, taking gains for the week to 5.3 percent, its biggest weekly advance since December 2011.

Trading volumes, which were sluggish through most of the day, picked up into the close and ended roughly in line with recent averages.

The rise by the FTSE 100 accompanied a rise in sterling, which hit a 2016 high.

Mining companies were among the top gainers, with the UK mining index up 2 percent following an increase in copper prices.

Shares (Berlin: DI6.BE - news) in Anglo American (LSE: AAL.L - news) , Antofagasta (Other OTC: ANFGF - news) , Glencore (Xetra: A1JAGV - news) and BHP Billiton (NYSE: BBL - news) all rose between 2 percent and 3.6 percent.

Britain's biggest retailer Tesco was up 0.8 percent, shedding part of earlier gains after reporting a second straight quarter of underlying sales growth in the UK - the first successive quarterly gain in more than five years.

"Tesco has maintained the positive momentum it picked up around the beginning of this year... against a challenging retail backdrop," said Laith Khalaf, a senior analyst at Hargreaves Lansdown (LSE: HL.L - news) .

Only around 10 stocks fell, with United Utilities (LSE: UU.L - news) down 2.6 percent as its shares traded without the attraction the latest dividend payouts. (editing by Larry King and John Stonestreet)