TORONTO -- Progressive Conservative Leader Patrick Brown will be sworn in as a member of the Ontario legislature Monday and take his seat in the chamber for the first time as MPPs return for the fall sitting.

Brown won a byelection Sept. 3 in Simcoe North, which borders the Barrie riding he had represented federally since 2006 until he won the PC leadership in May.

He's promising a "different approach" for the Official Opposition, insisting he won't oppose government initiatives simply because they're from the Liberals.

"It will not be blindly partisan at Queen's Park," he said. "When the Liberals act in the best interests of the province we will praise them, we will recognize a good action, but when it's not in the best interests of the province we will very clearly point out how we should take a different approach."

The Liberals used the byelection to portray Brown as too right-wing for mainstream Ontario, raising his voting record in Parliament on social issues such as abortion and same-sex marriage.

Brown insists he believes in a woman's right to choose and would block any attempt to reopen the abortion debate, and boasts he was the first PC leader to march in Toronto's annual Pride parade.

"The Liberals tried a negative smear campaign, tried to revisit social issues that are long settled, and the voters in Simcoe North, in a very resounding fashion, rejected that campaign," he said.

Government house leader Yasir Naqvi said if Brown really intends to do things differently he'd support the new Ontario pension plan and a cap-and-trade system that would put a price on carbon to reduce greenhouse gas emissions.

"It will be unfortunate if he does not (support the plans) because then he's just being partisan and not putting the best interests of Ontario ahead," said Naqvi.

The Tories oppose the "fire sale" of Hydro One because it will drive electricity rates even higher, said Brown, who called the provincial pension plan a "job killing payroll tax."

As Brown named his shadow cabinet last week, he appointed himself education critic but said he wouldn't rein in former leadership rival Monte McNaughton, who keeps attacking the updated sex education curriculum being introduced this year.

"I realize that there are those that want to talk about sex education ... but my focus is on jobs," said Brown.

The government's fall agenda will focus on jobs and the economy in addition to the pension plan and starting the sale of Hydro. There will also be a bill to protect the Great Lakes, another on land use planning and legislation to update the way police conduct background checks on people, added Naqvi.

The New Democrats have been campaigning hard against the sale of Hydro One since it was first announced, and will try again in the fall session to convince the Liberals they are going down the wrong road.

"Kathleen Wynne is turning her back on Ontario's proud history of public hydro to sell our oldest and most important public asset for a short-term, one-time gain," said NDP Leader Andrea Horwath.

The Liberals hope to raise $9 billion from selling 60 per cent of Hydro One, and will use $4 billion of that to fund infrastructure and public transit projects and $5 billion to pay down hydro debt.