EDMONTON -- Alberta's two conservative parties have taken the first step toward ending a decade of bitter feuding by signing a proposal to merge and become the United Conservative Party.

Wildrose Leader Brian Jean and Progressive Conservative Leader Jason Kenney announced the details of their unity deal Thursday at an Edmonton hotel.

The deal still has to be approved by 75 per cent of Wildrose members and just over 50 per cent of PC members. If it goes ahead, the new party will set up a leadership committee with an eye to electing a new leader on Oct. 28.

"The members will always be in the driver's seat," Jean said. "If approved by the membership, it would set us on a path to regain control of our province for now and for future generations."

Kenney said the proposed deal represents the reunification of a family that has been divided for too long. A united party, he said, would ensure the defeat of Premier Rachel Notley's NDP government.

"Hope is on the horizon," he said. "We are not seeking to impose an agreement but rather propose a way forward."

He spoke directly to PC members, some of whom have left the party in recent weeks, saying that they fear it's becoming less progressive and adopting a more socially conservative position.

Kenney himself fuelled those fears in late March when he said he favoured schools telling parents if their children joined a gay-straight alliance. Critics said telling parents could effectively "out" a child before they are ready and put them at risk.

"If this agreement is ratified, it's not the end of a proud legacy, but ... a fresh start and a new beginning," Kenney said.

Premier Rachel Notley said her party is focused on steering the province through the current downturn rather than making huge cuts to government programs, including health care and education, "to fund tax breaks for the top one per cent."

"That is not a path to recovery," she said at an announcement outside Calgary.

"I'm happy to have that debate with one right-wing party or 10 right-wing parties. It doesn't really matter. I'm confident that our choice to stand with Albertans is the right one."

Representatives from the Wildrose and PCs had been meeting since late March to hammer out an agreement.

Kenney won the PC party leadership on March 18 on a platform to merge. Both Kenney and Jean have said they'll run for the leadership of a consolidated party.

The plan is to have the parties vote on the deal by July 22.

A new party would move quickly to establish an executive and constituency boards in time for the next election which must be held in the spring of 2019. Notley has the option to call a vote earlier, but has stressed she plans to follow the law.

Political scientist Lori Williams said the question is whether the unified party can appeal to mainstream voters.

"Both of these leaders have a pretty major liability in that they are both social conservatives, and that's going to feed suspicions that this party is not going to be progressive," said Williams from Mount Royal University in Calgary.

"They'll just look like a new version of the Wildrose party."

Greg Clark, leader of and lone legislature member for the Alberta Party, said his party can be the new home for centrists.

"It's really important that we get it right in 2019, that we have a government that reflects modern Alberta values, that knows we can defend minority rights and balance the budget," he said.

The Wildrose emerged about a decade ago, founded by conservatives who felt alienated from then-premier Ed Stelmach's PC government.

The fortunes of both parties have since waxed and waned, usually at the other's expense.

Two PC members bolted to the Wildrose benches under Stelmach in early 2010, hastening his demise as leader a year later. In late 2014, Wildrose leader Danielle Smith and most of her caucus crossed the floor to the government benches when Jim Prentice was Tory premier.

The move backfired. The Wildrose rallied under Jean to win 21 seats in the 2015 election and retain its status as official Opposition.

The PCs finished third with 10 seats. None of the Wildrose floor-crossers made it back to the house.

Prentice quit politics and the election loss led the party to a reappraisal of its mission and ultimately to the election of Kenney.