By Ash Majithia Tory plans to change the threshold at which a household loses child benefit won’t fix the fact that some two-child families face a marginal tax rate of 73 per cent, say Ash Majithia and Tim Sexton It’s been framed as a hand-out for the wealthy, including executives in the City of London. But the real risk with the Conservatives’ plan to raise the threshold at which child benefits start to be taxed is that they simply move a tax trap further up the income scale. If re-elected, the Tories have said they would double the amount a household can earn before losing the payments from …