Alan Johnson has been appointed to the key role of shadow chancellor in Ed Miliband's first shadow cabinet.
The former home secretary will spearhead Labour's assault on Chancellor George Osborne's spending cuts after Mr Miliband drew back from appointing either Ed Balls or his wife Yvette Cooper.
Both had been widely tipped as possible candidates, with Mr Balls in particular having made no secret of his desire to take on the economic portfolio.
Instead he becomes shadow home secretary while Ms Cooper - who topped the shadow cabinet ballot of Labour MPs - gets shadow foreign secretary.
Despite his long Treasury experience, Mr Balls may have been seen as too independent, having already declared he would re-write former chancellor Alistair Darling's plans to halve the deficit in four years, slowing the pace of cuts.
Mr Johnson has a genuine popular touch and his appointment will be seen as an olive branch to the supporters of David Miliband, who he backed for the leadership.
In his first statement on taking up the post, he said he would not oppose Government measures "for the sake of it" and would work with Ed Miliband to develop a "real and responsible" alternative to the coalition's plans.
"We are both passionate about a new kind of politics where we will not disagree with our political opponents for the sake of it," he said. "These are testing times and we will be a responsible opposition acting in the national interest. Ed and I will work together to build a plan for growth and for jobs in our economy.
"We will offer a real and responsible alternative to the dangerous plans of this coalition Government which is damaging the economic future of millions of families."
Transport Secretary Philip Hammond however has dismissed him as a "caretaker appointment". He said: "Ed Miliband said that he wanted to move on to a new generation of Labour politicians - but Alan Johnson frankly is from the last generation of Labour politicians."