GEORGETOWN, P.E.I. -- Dennis King appealed for co-operation from his political opponents as he took office Thursday as Prince Edward Island's 33rd premier.

The Tory leader and his eight-member cabinet were sworn in by Lt.-Gov. Antoinette Perry during a ceremony held at the Kings Playhouse in Georgetown, P.E.I.

In an address before an appreciative hometown audience, King said a new era of Island politics is beginning with the first minority government in the province in well over a century.

"Islanders have given all members of this legislative assembly a mandate that requires co-operation and collaboration, with the necessity to work together for the best interest of Prince Edward Island," he said.

The Tories won 12 seats in the April 23 election, while the Green party won eight and the Liberals six, creating the first minority outcome in an election since 1890.

King said his government would face challenges ahead and stressed the need for cross-party co-operation through much of his speech.

"In the end, the success of Prince Edward Island during this mandate will be ultimately judged by the level of commitment of all three parties to work together," he said. "There is work to do. It's important work that people want us to do, and we must do it together."

He also urged his cabinet to work with collaboration in mind.

"I encourage you to lead with confidence and lead with humility," said King. "Be bold, be courageous, be different, be kind. Co-operate with your legislative colleagues and be open to good ideas."

King was sworn in with ministerial responsibilities for intergovernmental affairs, Indigenous relations, and Acadian and francophone affairs.

Darlene Compton is deputy premier, minister of finance and the minister responsible for the status of women, while James Aylward is the new health minister.

Others in cabinet include:

Steven Myers, minister of transportation, infrastructure and energy;

Jamie Fox, minister of fisheries and communities;

Matthew MacKay, minister of economic growth, tourism and culture;

Brad Trivers, minister of education and lifelong learning, minister of environment, water and climate change;

Ernie Hudson, minister of social development and housing;

Bloyce Thompson, minister of agriculture and land, minister of justice and public safety and attorney general.

Also on Thursday, Elections P.E.I. officially confirmed the provincial election results and said a byelection must be held no later than July 19 in the district of Charlottetown-Hillsborough Park.

The riding was left uncontested election night following the deaths of Green party candidate Josh Underhay and his young son in a boating mishap days before the vote.

Meanwhile, the third place Liberals confirmed late Wednesday that Robert Mitchell, who represents the riding of Charlottetown-Winsloe, has been named the party's interim leader.

First elected to the legislature in 2007, Mitchell held cabinet portfolios, including health and wellness, under former premier Wade MacLauchlan, who lost his seat to the new agriculture minister.

"I am aware of the work that must be done to rebuild and retool our party, and I am excited by the opportunity this presents for our caucus and our party", Mitchell said in a news release.

"Moving forward, our priorities will be to prepare for the upcoming legislative session and to connect with grassroots members across this province."