Melbourne (Reuters) - Australia s High Court rejected two legal challenges on Thursday against a proposed postal ballot on whether to legalize same-sex marriage, clearing the way for a vote on an issue that has wide support but which has also threatened to divide the government. Australians will now begin voting in the non-compulsory ballot as early as next week, with a result expected some time in November. The court s decision to reject the legal challenges, both of which argued that the center-right government needed the support of parliament to hold the ballot, comes as a welcome relief for Prime Minister Malcolm Turnbull. Turnbull supports same-sex marriage, as do two-thirds of Australians, but his government holds a razor-thin majority and more conservative elements in his Liberal-National coalition have used the issue to threaten his leadership. Some conservative lawmakers threatened to resign if the court ruled against the proposal, while more liberal members said they would side with the Labor opposition to secure same-sex marriage before Turnbull offered the postal vote as an alternative. A rejection would have led to increased pressure on Turnbull to hold a vote in parliament, which has already twice rejected a national ballot.  Every Australian can have a say and we can, as a Commonwealth of Australia, embrace this important social change,  Turnbull told parliament in Canberra after the court s decision was announced. Turnbull has said Australia s Marriage Act would be changed by the end of the year if the public backed same-sex marriage in the postal ballot. Although the court s verdict provides a viable pathway to same-sex marriage, advocates fear an escalation in an already vitriolic campaign. Turnbull called for mutual respect last month as the issue gathered heat. Opponents of same-sex marriage launched a contentious  No  campaign advertisement last week that the government immediately rejected as inaccurate. Activists fear a surge in malicious campaigning for the ballot, which is not a formal election and is therefore not subject to the usual rules on political advertisements. Many supporters of same-sex marriage in Australia had backed the legal challenges, insisting that the campaign would hurt people who were already vulnerable, but said they would now support the ballot.  We now get out there and campaign long and hard for a  Yes  vote,  Alex Greenwich, co-chair of Australian Marriage Equality, told reporters in Melbourne.  When we win this, we can all come together, having finally achieved marriage equality.   