but he declined to challenge Wilson. A year later his supporters again attempted to persuade Jenkins to challenge Wilson for the party leadership but he again declined. He later wrote in his memoirs that the 1968 plot was "for me...the equivalent of the same season of 1953 for Rab Butler. Having faltered for want of single-minded ruthlessness when there was no alternative to himself, he then settled down to a career punctuated by increasingly wide misses of the premiership. People who effectively seize the prime ministership – Lloyd George, Macmillan, Mrs Thatcher – do not let such moments slip". In April 1968, with Britain's reserves declining by approximately £500 million every quarter, Jenkins went to Washington to obtain a $1,400 million loan from the International Monetary Fund. Following a further sterling crisis in November 1968 Jenkins was forced to raise taxes by a further £250 million. After this the currency markets slowly began to settle and his 1969 budget represented more of the same with a £340 million increase in taxation to further limit consumption. By May 1969 Britain's current account position was in surplus, thanks to a growth in exports, a drop in overall consumption and, in part, the Inland Revenue correcting a previous underestimation in export figures. In July Jenkins was also able to announce that the size of Britain's foreign currency reserves had been increased by almost $1 billion since the beginning of the year. It was at this time that he presided over Britain's only excess of government revenue over expenditure in the period 1936–7 to 1987–8. Thanks in part to these successes there was a high expectation that the 1970 budget would be a more generous one. Jenkins, however, was cautious about the stability of Britain's recovery and decided to present a more muted and fiscally neutral budget. It is often argued that this, combined with a series of bad trade figures, contributed to the Conservative victory at the 1970 general election. Historians and economists have often praised Jenkins for presiding over the transformation in Britain's fiscal and current account positions towards the end of the 1960s. Andrew Marr, for example, described him as one of the 20th century's "most successful chancellors". Alec Cairncross considered Jenkins "the ablest of the four Chancellors I served". Public expenditure as a proportion of GDP rose from 44 per cent in 1964 to around 50 per cent in 1970.