Stephen Conroy with Opposition Leader Bill Shorten in 2015. Credit:Alex Ellinghausen He also identified the strain of dealing with the "24/7 media cycle" and incidents of being singled out in public and then "explaining to my young daughter why people have shouted abuse at her daddy in the street". After news of his resignation reached Mr Shorten in Canada, where he is meeting Prime Minister Justin Trudeau, a series of hurried tributes were issued from his office and those of Ms Plibersek, Penny Wong, Jenny Macklin, Wayne Swan and Kim Carr. "I have spoken to Stephen and he told me he has decided it is time to put his wife and daughter, who he loves so much, first. I admire and respect his decision. Stephen is one of my oldest friends. He's been a fearless provider of good advice," said Mr Shorten. On Friday, figures close to Senator Conroy in the Victorian Labor Party were painting his departure as "classic Conroy", an unexpected exit by a politician who was much humbler than his rambunctious and at time arrogant persona painted by the media.

Illustration: Ron Tandberg He was famously placed alongside Stalin and Mao Zedong on a tabloid front page when he attempted to drive through media reforms just as the Gillard Government began to unravel. Victorian Government minister Phil Dalidakis, a close ally, tweeted: "Like Frank Sinatra said, Conroy did it his way". But factional opponents sought to characterise his resignation as another self-interested move by the man dubbed by his one-time mentor Robert Ray, the former Labor senator, as a "factional Dalek". "The big question now is which new-generation factional Dalek he has already arranged to replace him," said a Labor source.

Victorian ALP general-secretary Noah Carroll did not return calls. It is expected that a female replacement will be found due to the Victorian Right's need to improve its adherence to affirmative action. Senator Conroy, along with Left powerbroker Kim Carr, have been stabilising influences over the Victorian party, including in Premier Daniel Andrews' caucus. Questions are now being raised about how this influence will continue on the caucus and what impact that will have on the Premier. Senator Conroy has been an important figure in cross-faction negotiations and party sources expect him to remain active in Victoria. The so-called stability pact - which sets out how seats will be carved up to avoid factional warring - is expected to remain in place despite Senator Conroy's departure.

"He's not actually dead", one influential figure in the Victorian ALP said. "The reality is in terms of power relationships within the party I don't think it makes any substantive difference." But others in the Victorian branch see the resignation, and Senator Carr's recent fall-out with the national Left, as part of a power shift in the state party, which may cause some problems for the Premier. A big field is expected for the preselection race, with some in Labor already calling for the replacement to be a woman to help boost the party's female representation. The Transport Workers Union and Senator Conroy will have a big say in who it may be, already the union's Bill Baarini, a former local councillor, has been linked to the vacancy. Senator Conroy is expected to announce his entry into the business world at boardroom or executive level, with some saying his intentions are mapped out in his final speech in which he nominated the NBN as his "greatest contribution" in politics.

Senator Conroy is known to be close to media mogul Kerry Stokes and the pair are skiing companions. He has also assiduously courted US interests as a long-time member of the Australian American Leadership Dialogue. In July, he accused China of "bullying": and urged Australia to join the US in freedom of navigation exercises in disputed areas of the South China Sea. His forthright stance contradicted Mr Shorten's. He was moved from the Defence portfolio in the latest reshuffle and placed in the more junior role of shadow special minister of state.

Nonetheless, Senator Conroy has been a key backer of Mr Shorten despite an up and down relationship. He was also critical to maintaining peace with the Left through a close friendship with Senator Carr, who he thanked in his speech. Senator Carr said: "Stephen was a factional rival, the fiercest of opponents. He became the most loyal of allies. Without him, it is possible that the ALP in Victoria could have been mired in defeat. But with him it became the most successful and the most stable branch in the country – an example for other states." With Richard Willingham