factors, including problems with the Home Insulation Program, a significant delay to a planned carbon emissions reduction scheme, the proposed introduction of the Resource Super Profits Tax, and the election of Tony Abbott as Leader of the Opposition. Senior Labor MPs conceded that the ALP's primary vote had dropped below 30% in some key marginal seats, a figure which if replicated at a federal election would have seen a Labor defeat. The leadership challenge was finally sparked after the influential Australian Workers' Union officially switched its support from Rudd to Gillard. AWU Secretary Paul Howes told the Australian Associated Press and ABC's Lateline that he and AWU President Bill Ludwig had decided to support Gillard as prime minister after making an assessment that a change in leadership was in the best interest of their membership. Challenge On the morning of 23 June 2010, NSW senator Mark Arbib, Victorians Shorten and David Feeney, and South Australian Don Farrell visited Gillard to tell her that enough Labor MPs and senators had lost confidence in Prime Minister Rudd to make a challenge feasible. By midday, Arbib and Feeney told Gillard that they could guarantee her the support of the majority of right-wing members from New South Wales, Victoria, Queensland, South Australia and Western Australia, giving Gillard enough support to win the leadership and become prime minister. Arbib and Feeney told Gillard that most of the Labor Party were convinced they would lose the next election if Rudd continued as prime minister. They also said that they believed Labor would be able to win with Gillard as prime minister. Party sources later told the Australian Broadcasting Corporation (ABC) that Gillard agreed that Labor faced electoral defeat with Rudd at the helm. After holding meetings throughout the evening, Rudd addressed the media at 10:30 pm to announce that Gillard had asked for him to either resign as prime minister or hold a leadership election the following day to determine the Leadership of the Labor Party. Rudd stated that a leadership election would take place the following day and that he would stand as a candidate. The Sydney Morning Herald reported that the final catalyst for the challenge against Rudd was "sparked by a report (in the Herald of 23 June) that Mr Rudd had used his Chief of Staff, Alister Jordan, to sound out the backbench over the past month on the level of support