Legislative leaders may get an unexpected gift from Congress as they struggle to raise enough money to pay for state government. The expansion of the state sales tax to Internet purchases could raise $20 million. Officials from Vermont’s largest banks are speaking out against a Shumlin Administration proposal to hike the franchise tax paid by the state’s five largest banks. A committee of the Vermont Senate is expected to complete work this week on a revenue bill that would limit how much a homeowner could deduct for mortgage interest when filing state income taxes.