UNION heavyweight Mark Rosenthal has a relaxing work routine.

Mr Rosenthal sidles into the office at 2pm every day, eats lunch and then goes to sleep at his desk.

"Then he wakes up, looks at his watch and says, 'I have to get out before the traffic gets bad.' He's usually out by 4pm after being at the office two hours," union vice president Marvin Robbins told The New York Post.

Mr Rosenthal earns $156,000 a year as president of a local municipal workers union in New York - a job he has held since 1998.

He has been in the news before. In 2009, Mr Rosenthal inspired a council bill requiring jumbo-sized ambulances for obese patients after he had a stroke at City Hall.

Union officials say the 400-plus-pound (more than 180kg) president racks up $1400 in food bills every month at the union's expense.

Executive board members told The New York Post Mr Rosenthal significantly over-orders at eateries and takes the extra food back to his apartment.

"He's always walking off with a doggie bag or extra boxes of food," said one board member.

Mr Rosenthal insists he works "12-to-14-hour days", and that allegations against him are "part of a smear campaign" by political opponents within the union.

He says it's normal for executives to take "power naps", and his meetings with the sandman can also be notched up to the effects of pain medication he takes for backaches, which he has suffered since falling through a chair at McDonald's last year.

"I'm 60 years old, so if I eat during my lunch hour and take a little medication, can't I close my eyes?" Mr Rosenthal said.

"Is it so outrageous?"

The union represents 3000 workers, many of whom are among the city's lowest-paid employees.

Those workers fork out more than $1080 in annual union dues, which help fund Mr Rosenthal's salary and perks.

Mr Rosenthal first won the union presidency in 1998 when he promised to rid the organisation of corruption and alleged mob ties. At the time, he called the union a "cesspool".

He has ruled with little opposition, in part because he has strong political connections at City Hall.

"There was always the fear that he'd use his power to retaliate against anyone who spoke up," said Joseph Puleo, another union vice-president who is now campaigning against Mr Rosenthal.

"He always likes to say he's a big supporter of Mayor Bloomberg and the fact that the mayor called him to thank him for his support when he was elected."

"I would love to see the Mayor's face if he saw the big sodas that he likes to drink. It's kind of ironic."

New York Mayor Michael Bloomberg famously tried to ban super-sized soft drinks last year.