Jim McCabe, leader of North Lanarkshire Council, had a quadruple bypass operation in January and has been absent from office for almost three months. The 73-year-old, who has recently given up smoking, has been making some visits to the authority's Motherwell headquarters but will not return until at least April.
Some have questioned the decision of Mr McCabe to return to such a high-pressure post and have expressed concerns to The Herald about the potential impact on the Labour veteran's health.
The Herald also understands there is a degree of political stasis within the council in Mr McCabe's absence. A fellow ward councillor, the SNP's Duncan McShannon, is also a long-term absentee due to ill health.
One source said: "Jim looks gaunt these days. And his age. I'd never have said that before."
However, officials at the council claim he is on the road to recovery and has signalled a desire to return.