Mr Doyle was City of Melbourne's longest serving Lord Mayor and was first elected to Melbourne City Council in November 2008. In November 2016, Mr Doyle was re-elected as Lord Mayor for a historic third term and was returned to Council with an increased majority.
City of Melbourne Acting Lord Mayor, Arron Wood, said: "All parties involved in these circumstances are very distressed and my thoughts are with everyone involved.
"Robert Doyle has made a significant contribution to the City of Melbourne and will leave an indelible mark on our City. He was deeply passionate about creating a vibrant, sustainable and forward-looking city that richly deserved its mantle as the world's most liveable city.
"We recognise that this is an extremely difficult time for Mr Doyle, his wife Emma Page-Campbell, and his four children. We are very hopeful that he has a full and speedy recovery from his current ill health."
City of Melbourne Chief Executive Officer, Ben Rimmer, said: "We will shortly notify the Minister for Local Government, Marlene Kairouz MP and the Victorian Electoral Commission of Mr Doyle's resignation and the requirement for an election for the position of Lord Mayor.
"We will provide further advice on the timing and process for election of a new Lord Mayor once those details are confirmed with the Commission. Mr Doyle's resignation does not impact the position of the Deputy Lord Mayor or any other Councillor and the Acting Lord Mayor will continue in that role until a new Lord Mayor is elected."
Mr Doyle's resignation follows advice from his lawyers late last week that he was suffering serious ill health and, as a result, additional time was required to finalise the current investigation into allegations made against him.
The investigation report has been drafted and was provided as a draft to Mr Doyle's lawyers for his review earlier last week, consistent with the ongoing engagement with Mr Doyle throughout the investigation.
Mr Rimmer is working to ensure that the report and its findings can be presented to Council for its consideration at the earliest available opportunity, consistent with procedural fairness to all parties.
Mr Rimmer said: "I recognise that it is in the interests of all involved and in the broader public interest that the full investigation report is completed as quickly as possible. Obviously there are many issues that are subject of current public debate that we cannot comment further on at this time, given the sensitive stage that the investigation process has reached and the rights and interests of all parties.
"However what I will say is that the investigation process commenced and was undertaken from a presumption of innocence, as it should. The whole purpose of the investigation is to ascertain the facts of the allegations. I cannot control the behaviour of the parties or of the media."
Melbourne City Council will meet tomorrow night, Tuesday 6 February, as the Future Melbourne Committee. At that meeting they will discuss a management report that covers broader issues emerging from the current circumstances.
Acting Lord Mayor, Arron Wood, said: "I am looking forward to discussing broader issues arising from these circumstances with my colleagues in the appropriate venue – a formal Council meeting.
"I'm sure we will consider how allegations of sexual harassment are handled under our current Council and State Government frameworks. All of us want to use these circumstances as an opportunity to identify gaps, improve our approach and ensure that Council is a safe workplace for men and women."
Fast facts:
Mr Doyle was first elected to Melbourne City Council in November 2008 on a leadership ticket with Councillor Susan Riley as Deputy Mayor. He was re-elected in November 2012, again with Councillor Riley as Deputy.
In November 2016, Mr Doyle was re-elected as Lord Mayor for a historic third term. On that occasion, he was returned with an increased majority and with Councillor Arron Wood as Deputy Mayor.
The management report to be presented to the Future Melbourne Committee is now publicly
available and recommends that Council review its Code of Conduct, particularly in relation to reporting and management of sexual harassment allegations and occupational health and safety matters involving Councillors.
It also canvasses issues that could be addressed to support timely and effective management of similar situations that may be faced by Victorian councils.