The man, in his mid to late 20s, placed the bet at a William Hill branch in the city and stands to make a potential profit of £24,000 at odds of 2/5.
Spokesman Graham Sharpe said: ‘And he wasn’t the only high-rolling ‘Remain’ punter in action - a client from South West Lonsdon who had already staked £20,000, added a further £20,000, so has now staked a total of £40,000 and stands to get back £54,120.’
But Hills have already taken one bet equal to the total amount staked by these two customers combined - as a central London-based female client has a bet of £100,000 on ‘Remain’ at odds of 2/5, which will return £140,000 if successful.
Mr Sharpe added: “Remain’ has fought back big-time today after a few days in which Leave has been making the running, but it is still the case that over 70% of all bets have been for Leave - while 73% of all stake money is on Remain. It seems the high-rollers fancy ‘Remain’ , the smaller money clients are overwhelmingly backing ‘Leave’.”