(Reuters) - Betting market odds on the U.S. presidential election have flipped to favour Republican President Donald Trump over Democratic candidate Joe Biden, according to data from two aggregators. Bettors on British betting exchange Betfair are giving Trump a 60% chance of winning a second term in the White House, up from 39% when polls opened on Tuesday morning. Biden’s odds of a win among bettors on the Betfair Exchange have fallen to 40% from 61% earlier. “Trump has overtaken Biden significantly and is now in pole position, suggesting it could be a very nervous night ahead for Biden,” Betfair spokesperson Sam Rosbottom said. UK-based Smarkets Exchange is giving Trump 65% win-odds, up from 39% when polls opened. Biden’s win-odds have fallen to 35% from 61% earlier. “This has mainly been driven by Trump seemingly holding the key swing state of Florida as a result of a very strong showing for him in the Miami-Dade county with a large Cuban population,” said Patrick Flynn, political analyst at Smarkets. Flynn said that Florida wasn’t a “must win” state for Biden as it was for Trump. “Biden could yet put those crucial Midwestern states of Pennsylvania, Michigan and Wisconsin in his column, and he would win the election.”