His farming parents, Michael and Mary, were Irish and raised him as a Roman Catholic: a religious background he would share with numerous other Australian communist officials.

[5] Elected to the executive of the CPA in 1926, he was dismissed from it the following year, when he resisted the change from a "united front" with the Australian Labor Party (ALP).

He was elected to the CPA's governing Central Committee and rose to prominence in the party, alongside his factional allies Bert Moxon and J.

[7] When Prime Minister Sir Robert Menzies declared the CPA illegal in June 1940, Sharkey and other party leaders went underground.

[8] In March 1949, Sharkey told a journalist for the Sydney Daily Telegraph that "if Soviet Forces in pursuit of aggressors entered Australia, Australian workers would welcome them.

Under his strong leadership he was able to ensure that the CPA did what many other countries' Communist parties failed to do, and minimised the impact of Nikita Khrushchev's repudiation of Joseph Stalin early in 1956, and of the Soviet invasion of Hungary later that year.

In November 1960, Sharkey attended the Meeting of 81 Communist and Workers Parties in Moscow, at which the CPA initially sympathised with the Chinese in the Sino-Soviet split.

[11] On 9 June 1965, Sharkey's resignation as general secretary of the Communist Party, due to ill-health, was accepted, and he was replaced by Laurie Aarons.

Sharkey was lauded by many in his wartime and post-war heyday as a hero[citation needed], but his reputation sank during the 1960s, along with the fortunes of the Communist Party as a whole.

In a 1999 book, the historian of Australian Communism, Stuart Macintyre, who had long since abandoned his own CPA membership, noted the hyperbolic way in which Sharkey was portrayed during the cult of personality period of the 1930s: