Council tax in Britain may need to rise by up to 5 percent a year for the next three years to keep services running and pay for social care reforms, an influential think tank has warned. The Institute for Fiscal Studies (IFS) said that under current government spending plans, a rise of at least 3.6 percent on council tax bills will be needed per year just for town halls to keep services running at the levels seen before the COVID-19 pandemic. But the researchers said this would likely be a minimum requirement, with extra cost pressures and demand potentially meaning bills could rise by up to 5 percent every year up to 2024/25. And they said social care aims announced by the government last month are currently underfunded and would cost £5 billion ($6.79 billion) a year in the long term—almost three times the additional funding allocated over the next …