Peter Rankin, leader of Preston City Council, will not stand for re-election in May.
The Labour leader of the local authority is facing a health battle having been diagnosed with a brain tumour last year.
Coun Rankin, who represents Tulketh ward, had stepped down temporarily as leader in December.
It was announced at Thursday's full council meeting that he does not intend to stand in the May elections as he is receiving treatment for the same type of brain cancer as Baroness Tessa Jowell.
The former Labour cabinet minister has recently spoken out about her experiences since her diagnosis.
Coun Rankin, who was not present in the chamber for the early minutes of the meeting, arrived later to applause from the elected members.
In a statement issued after the conclusion of the meeting, he said: "As many are aware, I had surgery for a brain tumour just before Christmas and have since started my treatment of chemo and radiotherapy.
"The doctors, nurses and support staff at Royal Preston Hospital have been amazing.
"I wish to pass on my heartfelt thanks to the many people who have sent me their kind thoughts and best wishes over the past few weeks.
"Where possible I am participating in meetings as council leader and intend for that to increase over the coming weeks.
"My cancer is glioblastoma and this is exactly the same as Tessa Jowell who spoke publicly about her serious illness last week. To me she is an inspiration and like her I am positive about getting rid of the cancer.
"Despite this, as this recovery will take quite a long time, I decided I cannot stand again for the Council in May.
"I have been leader since Labour took over in 2011 and faced many big issues over this period, including a very successful City Deal, regeneration and the very serious problems that government cuts have presented us with.
"It's been an honour to have served as council leader but hard work. It's now time to concentrate on my serious health issues."