Around 2.5 million people could still pay tax on their state pension if the Conservatives’ proposed “triple lock plus” policy is put in place, a former Liberal Democrat pensions minister has said. The Conservatives unveiled plans to boost pensioners’ incomes with a new ‘triple lock plus’ pledge in an attempt to rally support from older voters ahead of the General Election. The new policy would raise the tax-free pension allowance every year in line with the triple lock. Under the triple lock, the state pension increases each year in line with average wages, inflation, or 2.5 per cent – whichev…