The FTSE 100 matched global stock markets and rose sharply as bullish investors piled back into equity markets after concerns of a British exit from the European Union eased over the weekend.
London's premier index was up over 2%, rising 130.6 points to 6151.8 in morning trading, bouncing back from last week's losses after opinion polls begin to point towards Britain remaining in the EU.
Housebuilders, banks and airlines saw the biggest gains on the FTSE, with Land Securities rising 4.09% to £11.44, Royal Bank of Scotland gaining 6.98% to £2.37 and British Airways owner International Consolidated Airlines up 4.6%.
Investors are feeling more confident after the first opinion polls since the murder of Labour MP Jo Cox suggest the Remain campaign is mounting a fightback following a two-day suspension in campaigning.
Sterling also saw big gains against the dollar, rising 1.71% against the greenback to 1.46 US dollars on Monday morning, one of its biggest rallies since the financial crisis. The pound has now erased nearly all its losses from the past two weeks.
Joe Rundle, head of trading at ETX Capital, said that investors are reacting to the poll data.
"Three polls over the weekend showed a tangible swing back towards Remain and it looks like investors are reacting to these data. If sterling is anything to go by, markets well and truly think voters have swung in favour of Remain," he said.
The rise on the FTSE was mirrored in Europe, with Germany's DAX up 2.68% and the French CAC up 2.5%
Japan's benchmark Nikkei 225 index surged 2.3%, while Hong Kong's Hang Seng and Australia ASX added 1.7%.