LONDON (Reuters) - Prime Minister Theresa May pledged on Friday to fight for the “precious, precious union” of the United Kingdom, unveiling what she called her Plan for Britain with a warning to Scotland not to pursue its independence plans.

Britain's Prime Minister Theresa May speaks at the Conservative Party's Spring Forum in Cardiff, Wales, March 17, 2017. REUTERS/Rebecca Naden

May, appointed prime minister soon after Britain voted to leave the European Union in a referendum last June, said she would negotiate a Brexit deal for the whole country but needed everyone to pull together to get the best outcome.

Facing two years of what are likely to be difficult talks for Britain, May wants to stamp her authority on a new agenda for the country but is struggling to repair the deep divisions exposed by the Brexit vote.

Nationalists in Scotland have condemned her move to block their demands for a new independence referendum before the EU talks end as an “outrage”, and Northern Ireland’s largest Irish nationalist party says it wants a vote on splitting from Britain after both regions voted to stay in the bloc.

“The coming negotiations with the EU will be vital for everyone in the United Kingdom ... It is essential that we get the right deal, and that all of our efforts and energies as a country and focused on that outcome,” May told her party.

“We need to do so united, as one United Kingdom, all pulling together to get the best outcome,” she said, promising to ensure all the voices and interests in England, Scotland, Wales and Northern Ireland are represented.

“I will always fight to strengthen and sustain this precious, precious Union,” she added.

It will not be an easy fight.

The ruling Scottish National Party (SNP) in Edinburgh has refused to back down over its demand for a new independence vote after May said: “Now is not the time”.

Angus Robertson, deputy leader of the SNP, received a standing ovation at the party’s conference in Aberdeen when he said: “Scotland’s referendum is going to happen, and no UK prime minister should dare to stand in the way of Scottish democracy.”

In her speech, May tried not to linger on the complexities of Brexit, saying simply she would adopt a “phased approach” to deliver a “smooth and orderly Brexit” and offer certainty wherever possible.

Instead, she wanted to reinforce her pitch for the political center ground and move the conversation away from the EU and Scotland. She pledged to boost technical training, reform energy markets and increase selective schools.

“Our Plan for Britain is a plan for a brighter future,” she said.