Global markets rebounded after the FBI said it found no evidence of criminality in a new batch of Hillary Clinton emails, boosting her campaign days before the US presidential election.
FBI director James Comey told Congress over the weekend the agency's review had found nothing to alter its original conclusion in July that Clinton had been careless, but not criminal, in handling sensitive material on her private email server while secretary of state.
The FTSE 100 Index opened more than a 1% higher, or 85.3 points to 6778.5, as traders bet that Donald Trump's Republican presidential campaign would lose the momentum it had gathered last week following the revelation.
Many investors fear a Trump presidency would lead to higher tariffs, currency wars and tighter controls on immigration.
The FTSE 250 Index lifted 112.7 points to 17384.
Overnight markets in Tokyo and Sydney jumped by more than 1%, while this morning Germany's DAX and the Cac 40 in France were also both more than 1% higher.
Spreadex financial analyst Connor Campbell said: "With the FBI reaffirming their conclusion that the Democratic candidate displayed no criminal wrongdoing in her use of a private email server, the markets seemingly let out a sigh of relief this morning.
"The thinking will be that this news may well swing any undecided voters back towards Clinton, therefore lifting her already substantial chances of winning Tuesday's election."
Blue chip stocks lost £76bn
This moves come after blue chip shares in London last week lost £76bn in value after the race for the presidency narrowed in Trump's favour following the FBI's dramatic news that it would launch another probe into Clinton's emails.
The Footsie lost 303 points, or 4.3%, last week – the worst weekly performance since the start of January.
In morning trading the biggest risers in the FTSE 100 Index were BHP Billiton (+48.5p to 1214.5p), HSBC (+23.2p to 618p), Antofagasta (+19.5p to 551p), Rio Tinto (+93p to 2820.5p) and Anglo American (+30.5p to 1102.00p).
The biggest fallers in the FTSE 100 Index were Fresnillo (-33p to 1592p), Tesco (-2.6p to 200p), Randgold Resources (-80p to 6710p), Coca-Cola HBC (-15p to 1713p) and Hikma Pharmaceuticals (-8p to 1618p).
In morning trading the biggest risers in the FTSE 250 Index were Kaz Minerals (+12.7p to 291.6p), Vedanta Resources (+22p to 736.5p), Evraz (+5.5p to 193.4p), Temple Bar (+31p to 1121p) and Petra Diamonds (+4p to 147.5p).
The biggest fallers in the FTSE 250 Index were Lancashire Holdings (-17p to 703p), Hochschild Mining (-5.5p to 259.7p), esure Group (-3.6p to 189.8p), Acacia Mining (-8p to 513p) and CLS Holdings (-24p to 1566p).