Xuereb was born at Rabat, Malta and studied at St Aloysius College and at Flores College. He also read English literature and public administration at the City Literary Institute and the Regent Street Polytechnic of London (1946-49). Xuereb worked as clerk at the Dockyard and at the Inland Revenue department, London and was also visiting master at the Lyceum, Malta.
Between 1959 and 1964, Xuereb was editor and assistant editor of the MLP newspaper The Voice of Malta. In 1962, 1966, and 1971 he successfully contested the general elections with the MLP but had to win casual elections in 1976 and 1981. In 1971 he was chosen as parliamentary secretary at the office of the prime minister, whilst in October of the same year he was given the portfolio of minister of trade, industry, agriculture, and fisheries. Xuereb resigned from parliament on 27 April 1983 to open the way for the co-option of the designate leader of the MLP, Dr Carmelo Mifsud Bonnici. On 15 July 1986, he was nominated Speaker of the House of Representatives, which office he held up to 13 February 1987 when he was appointed acting president of the Republic, an office he held until 1989.
Xuereb was chairman of Mid-Med Bank; Medigrain; Investment Finance Bank; and Malta Development Corporation.
Xuereb published a good number of novels and short stories. These include Meta... which won him the Malta Literary Award. Many of his writings can be found in The Knight, L-Ideal, and Ix-Xewka.