By Jack Barnett The government has put a windfall tax on the UK’s largest banks on the table, sending their shares plummeting today. London-listed Lloyds Bank, which is Britain’s biggest mortgage lender, plunged to the bottom of the FTSE 100 index today, shedding 4.11 per cent. Previously state-owned NatWest trailed closely behind on the biggest losers’ table, dropping 2.92 per cent. Chancellor Jeremy Hunt is considering imposing a temporary tax on UK banks’ profits in a bid to raise revenue for the countries’ depleted public finances, according to the Financial Times. A treasury spokesperson …