CALGARY, Alberta, Sept 17 (Reuters) - Battered but unbowed, Canadian Prime Minister Stephen Harper has momentum and the economy on his side as he heads into the second leaders' debate later on Thursday, hoping a home-turf advantage will help him break away from centre-left opponents.
The debate offers a pivot point for Harper, 56, as he recovers his footing following a string of scandals and bad news in the first half of the campaign for the Oct. 19 federal election.
Harper trumpeted an early federal budget surplus this week, saying his Conservative party was best poised to manage the economy.
And his offer of limited help to Syrian refugees has found support among the party's base, even as his opponents say Canada should be more generous.
Monday's surplus news brightened the mood on the campaign trail, with staffers joking that opponents would be scrambling to come up with any viable economic argument to throw at Harper.
Polls show a tight three-way race ahead of vote, with a minority government likely.
The debate, which focuses on the economy, will take place in Calgary, Harper's adopted hometown, where he maintains a solid base albeit a disgruntled one in the wake of a prolonged slump in oil prices.
Harper, seeking a rare fourth term and battling voter desire for change, will face New Democratic Party leader Thomas Mulcair, 60 and Liberal leader Justin Trudeau, 43. Green Party leader Elizabeth May, left off the roster, said she would "join" in a post on Twitter.
Criticized in the past for seeming aloof, Harper donned a casual Team Canada jacket at events this week, opening rallies with off-the-cuff jokes and appearing relaxed.
After a series of campaign missteps, he has double downed on fiscal management with a new 'Protect the Economy' slogan and a series of ads in which he discusses taxes at the dinner table with Canadians.
"The world is an unstable and dangerous place. The global economy is weak and in turmoil," Harper told a huge crowd in Calgary. "If we get our economy wrong, no matter what the Liberals and NDP say, we cannot borrow and tax our way back to prosperity."
The Liberals' Trudeau, who performed well in the first debate in August, will be looking to shore up support with another strong showing, while NDP's Mulcair, known in Ottawa as a passionate orator, is expected to come out swinging after a tepid performance.
Among Harper's supporters, the decision is clear.
"Harper's an economist, Trudeau's a social worker and Mulcair's a lawyer. Who are you going to trust with the economy?" said Allan Lees, a small business owner in a Vancouver suburb, who plans to vote Conservative.
The debate kicks off at 8:00 p.m. ET (0000 GMT) and is hosted by the Globe and Mail newspaper.
$1 = 1.3245 Canadian dollars Editing by Bernadette Baum