[1] In June 1903, Jensen was admitted to the membership of the Tasmanian Workers' Political League – the forerunner of the Australian Labor Party in Tasmania – after attending the organisation's inaugural state conference and signing the pledge required of parliamentary members.

[3] He was appointed Chief Secretary in John Earle's eight-day government in June 1909, the first time the ALP had held office in Tasmania.

In June 1918 he published "an extensive report on Australia's trade representation abroad that would link with but not rely upon the British consular service".

He had three further children from his second marriage, one of whom predeceased him, and according to the Australian Dictionary of Biography was "at times violent at home and showed his second wife little affection".

[1] Jensen suffered from diabetes later in life and died of cerebrovascular disease on 16 November 1936 at a private hospital in Caulfield South, Victoria.

Jensen settled the majority of his estate on Gilbert, with four of his children subsequently lodging a caveat against the will on the grounds of undue influence.

They further alleged that Jensen had given Gilbert almost all of his property and wealth prior to his death, including a block of flats at Beauty Point, an estate in northern Tasmania, and valuable shareholdings.

[8] Jensen's widow Bertha was called as a witness and stated that her husband had physically abused their children, including with a horsewhip, as well as alleging that Gilbert had tried to poison him.

[9] The presiding judge Charles Duffy ultimately granted probate and removed the caveat, finding that the claim of undue influence had not been made out although he accepted the evidence of Jensen's widow and children as to his character and personal life.