Why IFS boss Paul Johnson counts in this tightest of general elections

Oxford peer of Ed Balls matters because the Institute for Fiscal Studies is seen as the ultimate arbiter on range of issues that will have a bearing on the result

Any list of the people that matter in this tightest of elections would include Paul Johnson. Few voters would be able to identify him, but the director of the Institute for Fiscal Studies is up there with David Cameron, Ed Miliband, Nick Clegg, Nigel Farage, Natalie Bennett and Nicola Sturgeon. He is a man who counts.

Johnson matters because the IFS is seen as the ultimate arbiter on a range of issues that will have a bearing on the result on polling day: government spending totals, tax, the size of the budget deficit and living standards. In short, whether the plans of the Conservatives, Labour and the Liberal Democrats stack up.And it didn't take long for the IFS to be called into action. When Cameron formally launched the Conservative election campaign today with a claim that Labour would raise taxes by 3000 for every household, Johnson said it was "unhelpful". An instant bit of IFS number-crunching concluded that Labour was planning nothing of the sort.

Related: Cameron's warning on Labour's 3,000 'tax rise' is shot down by IFS

They like to quote our numbers at ""prime ""minister's questions. I don't get too upset about it