Eight years after taking the reins as Vancouver's mayor, Gregor Robertson's approval rating has certainly seen better days.

In fact, the Vision Vancouver leader is currently the least popular big city mayor in Canada, according to a new poll released by Mainstreet Research Monday.

The survey found Robertson's approval rating sits at just 50 per cent, while the most popular mayor, Ottawa's Jim Watson, enjoys an approval rating of 79 per cent.

Robertson's supporters still outweighed his detractors, however, with 45 per cent of survey respondents disapproving of the job he's doing and five per cent reporting that they aren't sure.

"Overall, every Canadian mayor we polled has a net positive approval rating – though some mayors are faring radically better than others," Quito Maggi, president of Mainstreet Research, said in a release.

Saskatoon Mayor Charlie Clark, who was just elected last fall, was the second-highest rated, with an approval rating of 72 per cent.

Back in 2009, the year after Robertson was elected mayor, another polling company pegged his approval rating at 70 per cent.

And while the Vancouver mayor's popularity may have dipped, it's still not the lowest of any mayor in the country. That dubious honour belongs to Matt Brown, mayor of London, Ont., according to a separate Mainstreet poll conducted after Brown was caught having an extramarital affair with his deputy mayor last year.

"Brown's disapproval was a staggering 58 per cent, which translated to a net score of -25," Maggi said.

The latest poll only covered Vancouver, Calgary, Edmonton, Saskatoon, Regina, Winnipeg, Windsor, Toronto, Ottawa and Montreal.

The survey, conducted on behalf of Postmedia News, polled a random sample of 6,103 Canadians from Jan. 3-4 using a mixture of landlines and cellphones. The margins of error in the different cities varied from plus or minus 3.91 to 4, 19 times out of 20.