Most Albertans believe Stephen Harper is a better defender of Alberta's interests than Premier Rachel Notley, according to a new poll, amid increasing pessimism about the province's economy.

Fifty per cent of Albertans give the nod to the federal Conservative leader on that question, compared to 33 per cent who favour Notley, the leader of Alberta's New Democrats, according to a poll conducted by Mainstreet Research.

Residents are split about the job Notley is doing as premier, with 42 per cent saying they disapprove and 45 per cent saying they approve — down from 62 per cent approval in May.

"Recent economic factors, primarily a continued slide in oil prices, are likely a factor in the increased disapproval," said Quito Maggi, president of Mainstreet Research.

"How the Notley government responds to this new challenge will be the first big test of her government. So far, Albertans are waiting to see the specifics of her plan which will be unveiled in the fall budget," he added.

Despite the economic woes, almost half of Albertans — 47 per cent — still support the NDP government's plan to review energy royalties.

Economic gloom

The poll also showed a sharp drop in optimism among Albertans — both for the province and people's own households.

Only 21 per cent of Albertans are optimistic about Alberta's economy, down 20 percentage points from May. Forty per cent are optimistic about their family's financial future, a 12 percentage point drop.

When asked whose economic policies they favoured, 50 per cent of Albertans sided with Harper, while 36 per cent favoured the policies of Notley's NDP government.

Of those surveyed, 38 per cent said the government should cut spending levels to avoid increasing the provincial deficit, while 26 per cent want to maintain or increase spending levels to protect public services. Only 10 per cent support raising taxes and other revenue sources.

The poll also shows a regional divide in support for the two leaders.

"Premier Notley fares best in, no surprise, Edmonton (48 per cent Notley, 36 per cent Harper) where Stephen Harper fares worst. Meanwhile, Harper receives his highest score ... from Calgary (59 per cent)," Maggi said.

The poll surveyed 3,075 people and has a margin of error of +/- 1.8 percentage points, 19 times out of 20.