Philip Hammond must find an extra £5bn in this year’s Whitehall spending review to reverse planned cuts and meet his claim of ending austerity, a leading thinktank has revealed. The Institute for Fiscal Studies told the chancellor that funds pledged in last year’s budget to boost NHS spending, defence and international aid failed to safeguard local councils and some of the worst-hit government departments from further shortfalls. The thinktank said a minimum of £2.2bn would be needed to freeze all…