leader Morgan Tsvangirai accused Mbeki of being a "dishonest broker" and his government of becoming "part of the Zimbabwe problem because its actions are worsening the crisis." Commentators later said that Mbeki's soft stance on Mugabe during this period permanently damaged relations between South Africa and the Zimbabwean opposition. A South African government observer mission also endorsed the result of the Zimbabwean parliamentary elections of 2005, apparently leading Tsvangirai's party, the Movement for Democratic Change (MDC), to effectively sever relations with Mbeki's administration. Power-sharing negotiations Following another contested election in Zimbabwe – after which Mbeki controversially denied that there was a "crisis" in Zimbabwe – the MDC and ZANU-PF entered into negotiations towards the formation of a power-sharing government, with talks beginning in July 2008. Mbeki mediated the negotiations and brokered the resulting power-sharing agreement, signed on 15 September 2008, which retained Mugabe as president but diluted his executive power across posts to be held by opposition leaders. HIV/AIDS Policy and treatment According to political scientist Jeffrey Herbst, Mbeki's HIV/AIDS policies were "bizarre at best, severely negligent at worst." In 2000, amid a burgeoning HIV/AIDS epidemic in South Africa, Mbeki's government launched the HIV/AIDS/STD Strategic Plan for South Africa, 2000–2005, a "multi-sectoral" plan which was criticised by HIV/AIDS activists for lacking concrete timeframes and failing to commit to antiretroviral treatment programmes. Indeed, according to economist Nicoli Nattrass, resistance to the roll-out of antiretroviral drugs for prevention and treatment became central to the HIV/AIDS policy of Mbeki's government in subsequent years. A national mother-to-child transmission prevention programme was not introduced until 2002, when it was mandated by the Constitutional Court in response to a successful legal challenge by the Treatment Action Campaign. Similarly, chronic highly active antiretroviral therapy for AIDS-sick people was not introduced in the public healthcare system until late 2003, reportedly at the insistence of some members of Mbeki's cabinet. According to Nattrass, better access to antiretroviral drugs in South Africa could have prevented about 171,000 HIV infections and 343,000 deaths between 1999 and 2007. In November 2008, a Harvard University study estimated that more than 330,000 people died between 2000 and 2005 due to insufficient antiretroviral programmes under Mbeki's government. Even after these programmes were introduced, Mbeki's appointee as Minister of Health, Manto Tshabalala-Msimang, continued to advocate publicly for unproven alternative treatments in place of antiretrovirals, leading to continual calls by civil society for her dismissal. In late