Alistair Darling has said there was a "deeply unpleasant" atmosphere at the heart of Gordon Brown's government after he and the then prime minister fell out over the severity of the 2008 economic crisis.
The former Labour chancellor was speaking on the BBC's Andrew Marr programme while promoting his new political memoir 'Back From The Brink: 1000 Days at Number 11'. The book characterises Brown's Downing Street operation as one of "chaos and crisis".
Darling served as chancellor under Gordon Brown from 2007 until 2010. In an extract featured in The Sunday Times he writes of Brown's time in Number 10: "It was a fairly brutal regime, and many of us fell foul of it."
In the book claims that Brown believed that the 2008 financial crisis would be over in six months and refused to sanction public spending cuts that the then chancellor believed necessary.
Speaking on Sunday, Darling suggested Labour could have won the 2010 election if Brown had set out a "credible" economic policy.
"The object lesson here is for any government to operate there needs to be complete unity at the top," he said. "My frustration is we could have got through this, we could have charted a political way through it."
He added: "You need to be united at the top but you also need a credible economic policy...it was so blidnlingly obvious that the two of us were at odds it hampered us at the election."
In 2008 Darling gave an interview to the Guardian in which he warned the economic crisis could be the worst the country had seen for 60 years. Following the interview he said Downing Street unleashed the "forces of hell" against him as Brown was unhappy with his analysis.
"It was deeply unpleasant," Darling told Marr. "I really don't mind, and relish, attacking Tories and them attacking me. What is so debilitating is when your own lot are doing it to you. It left a mark on me you really can't erase."
Asked why he did not try to force Brown to change his view or even try to push him out of power, Darling said he "had a residual loyalty [to Brown] which i found very difficult to overcome, we go back a long long way".
Extracts from the book also reveal Darling's frustration with Britain's bankers at the height of the financial crisis. He writes that at one point he was worried "they [the bankers] were so arrogant and stupid that they might bring us all down".
Seizing on the chance to remind the public of the discord at the top of the previous government, Conservative MP Greg Hands, a parliamentary aide to Chancellor George Osborne, said Labour had failed to learn from past mistakes.
"It shows Gordon Brown at the time failing to acknowledge the seriousness of the UK's economic position, a mistake being repeated now by his protégé Ed Balls, who's still calling now for more spending," he told Sky News.
But Andy Burnham, the shadow education secretary, said the coalition government was "supping the life out of the economy" by cutting public spending too quickly and by too much.
He told Sky News: "We believe the government is going too far and too fast".
Burnham, who was a candidate in the 2010 Labour leadership election, admitted there had been "too much factionalism" in the dying days of the last Labour government, but said he did not want to continue "raking over these coals".
"We're a new team and we are coming forward to rebuild the Labour Party," he said.
Darling is not the first senior Labour figure to criticise Brown's premiership in a memoir. Tony Blair, Peter Mandelson and Alistair Campbell have all put the boot in to the former prime minister.