The 37-year-old, considered to be a rising star of the Labour Party, tendered his resignation today at a meeting of the authority's Labour group at the City Chambers.

Purcell had been involved in Glasgow's successful bid which saw the city beat Nigeria's capital Abuja to be awarded the Games by the Commonwealth Games Federation (CGF) at its meeting in Sri Lanka in November 2007.

Purcell has employed crisis management specialist Jack Irvine, of Media House, and a lawyer to handle his resignation.

Deputy leader Jim Coleman will take the role of acting leader until the Labour group’s annual general meeting after the General Election, which is expected to be held in May.

He said: "My job is to continue the good work Steven started and make sure it’s business as usual for Glasgow.

"Glasgow will go forward and continue the work Steven started.

"We will continue to drive forward the agenda for change in Glasgow and I am confident we will deliver the Commonwealth Games in 2014."

Purcell put ambitions of a political career at Westminster or Holyrood on hold to deliver the £300 million event, which includes building a string of new sports venues and a £2 billion upgrade of the city's transport infrastructure.

Glasgow 2014 will be the biggest event Scotland has staged in its history.

Having such a central role in the Games was among the main factors affecting Purcell's health, his friends claimed.

Purcell, who left his wife and came out as gay in 2006, had been working closely on the project since being chosen as Leader of Glasgow in May 2005.

A spokesman for Purcell said: "Steven’s family and close friends came to his home at the weekend.

"They were deeply concerned about the enormous stress levels he was displaying.

"Steven agreed the pressures surrounding...the Commonwealth Games were enormous and that he was totally exhausted.

"Steven agreed to seek medical help immediately and is now under doctor’s orders.

"He would hope to get back into active politics in the next few weeks and months.

"He hopes the people of Glasgow will appreciate what he has tried to do for the city he loves."