In 1969, the IWBP leader, then the Chief Minister, Sir Robert Peliza, was the mover of the Preamble to the Constitution[3] which safeguards Gibraltar from ever passing to Spain without the expressed wishes of the Gibraltarians.

He became the Branch Officer for the Transport and General Workers Union (responsible for the public sector in Gibraltar and was the main force behind the attainment of parity of wages with the UK for Gibraltarians).

His re-election in 1992 with a 72% share of the vote (using the campaign slogan "Give Spain No Hope"), caused considerable friction with governments in both London and Madrid who were looking for a solution to the 30-year-old Spanish claim to Gibraltar.

During his time in office, Bossano also oversaw significant economic change, resulting from the decline of traditional sources of employment, such as the UK Ministry of Defence, and the creation of a private sector economy based on offshore finance and tourism.

[citation needed] He helped resolve the severe housing problem existing in Gibraltar before he came into power, by reclaiming land from the sea and constructing hundreds of affordable flats, which were offered at very reasonable prices.

[8] The GSLP-Liberal government under Fabian Picardo won a second term at the 2015 general election and as of 2017, Bossano held the position of Minister for Economic Development, Telecommunications & the Gibraltar Savings Bank.

[10] In 1992-1993, when serving as Chief Minister, he told local media that if international law states that a Moroccan man, with his "4 wives and 10 kids", are required to enter Gibraltar easily, he responded saying that he and his family would not come.

The Moroccans were pivotal for Gibraltar for some time since they replaced the Spanish workers lost when the border closed in 1969 and the vast majority were still living and working in squalid, inhumane conditions 30 years on.