Can Osborne make the move from No 11 to No 10?

As if he were not under enough pressure already, George Osborne is now being widely tipped in Tory circles as the next party leader, with William Hague effectively out of the running and no other obvious contenders in sight. Making the step up from Chancellor to Prime Minister is not easy – if the economy is in good shape, there is probably no reason for the PM to leave office and, if it is in a mess, the Chancellor must share the blame. But some have made the transition. There have also been some notable failures.

John Major

The sacking of Geoffrey Howe in July 1989 and the resignation of Chancellor Nigel Lawson that September, meant John Major was propelled to the top end of the Cabinet table, but had not been there long enough to be associated with the unpopular poll tax. He presented one Budget and made one major decision, to enter the European Exchange Rate. When that turned into an unmitigated disaster, Major was already in 10 Downing Street and his successor as Chancellor, Norman Lamont, took the blame.

Jim Callaghan

Sunny Jim had a bad time as Chancellor after Labour returned to power in 1964. Sterling had been locked for 20 years in a complicated system of controls known as Bretton Woods and was a constant target of currency speculation. As he took office, Callaghan flatly ruled out devaluation. Instead the Government struggled to find a "third way" out of the crisis, until eventually, in November 1967, they were forced to give in. Callaghan insisted on resigning immediately although the Prime Minister, Harold Wilson, did not want him to. It was a shrewd move, which meant that Wilson took the large share of the blame for the Government's humiliation and Callaghan spent the next nine years in important but less vulnerable positions until his chance came.

Gordon Brown

No one was ever more desperate for the top job than Gordon Brown, who skulked in 11 Downing Street for 10 years, trying to find a way to persuade the bloke next door to move out. Though he was the last person to appreciate it, he was lucky to be teamed up with one of the few prime ministers in modern times who was not forced out in an election or by a political crisis. The careers of Gordon Brown and Tony Blair were interlinked so closely that if Blair had been brought crashing down, Brown would almost certainly have fallen with him. As it was, there was a painless handover of power. The pain, as we know, came later.

Denis Healey

Arguably there was no one in the Labour Cabinet in the late 1970s better qualified than Denis Healey to be Prime Minister. He had the intellect and the experience that came from running the Ministry of Defence and the Treasury, two of the most difficult departments for any Labour minister to handle. He also had the ambition and the backing of the incumbent, Jim Callaghan, who timed his resignation to maximise Healey's chance. But within the Labour Party, he was held responsible for the drastic spending cuts imposed by the International Monetary Fund in 1976 as a condition for an emergency loan. Healey had to settle for being deputy leader of the party, under Michael Foot.

Roy Jenkins

Roy Jenkins took over in the Treasury after Callaghan's resignation in 1967, and handled the economy with great skill. He had one of the finest brains in the Cabinet, he was more popular with the public than the Prime Minister, and there were MPs ready to back him had he decided to challenge Harold Wilson. But he never quite decided to go for it. In 1970, he could have introduced a giveaway Budget that might have secured Labour another term in office, but he did not want to take risks with the economy. He was less popular in the party than in the country, and by 1974 it was clear that Jenkins's chances had passed.

Ken Clarke

For many years, the Tories have attributed the early successes of the Blair-Brown government to the benign economic climate left to them in 1997. In the circumstances, it might be thought that they would want to give recognition to the Chancellor who presided over the spectacular economy recovery that followed the disaster of sterling's ejection from the Exchange Rate Mechanism in 1992. Ken Clarke ran for the leadership in each election that followed a general election defeat in 1997, 2001, and 2005; always losing to less experienced and less well-known rivals, because the party could not forgive him for his pro-European views. When it finally looked as if they might forgive and forget and turn to Clarke, a young contender named David Cameron popped up from nowhere.