Challenging her critics, British PM May embraces Brexit "opportunity" (UPDATE 2)

British Prime Minister Theresa May will tell her Conservative Party on Wednesday the impending divorce from the European Union is an opportunity that opens up a future of promise, assuring the faithful: "We have everything we need to succeed."

On the final day of her party's conference, May will take aim at her critics, who accuse her of failing to embrace Brexit and of giving in to the EU.

The leader's fragile position has been put under further pressure over the last month after the bloc rejected parts of her so-called Chequers plan and critics have stepped up calls for her to rethink her strategy for Brexit, the biggest trade and foreign policy shift in Britain for more than 40 years.

But with just six months before Britain is due to leave the bloc, she has so far weathered the Brexit storm, shrugging off a barnstorming speech by her former foreign minister Boris Johnson, which did little to hide his leadership ambitions.

"I passionately believe that our best days lie ahead of us and that our future is full of promise," she will say, according to excerpts of her speech.

"Don't let anyone tell you we don't have what it takes: we have everything we need to succeed."

The words may do little to ease the growing frustration of some Conservatives who openly say their party is directionless, but with Brexit talks entering a critical phase, few of her rivals want the top job just yet.

Less than an hour before she was due to speak, Conservative lawmaker James Duddridge said he had submitted a letter to the party's so-called 1922 committee, calling on May to resign.

Forty-eight lawmakers would need to write such letters to trigger a vote of confidence in the leader.

"Turns out there is a plan. That plan is Boris," Duddridge wrote on Twitter after Boris Johnson's speech on Tuesday.

In the speech, Johnson seemed to pull his punches, backing May for now after he made a rallying cry for the party to return to its traditional values and to "chuck Chequers".

And her allies were keen to present a united front.

"I sit in a cabinet that is utterly united in working with the prime minister on the proposals we've put forward to the EU," said David Lidington, her effective deputy.

'SORRY FOR HER'

John Smeaton, 80, a Conservative member from Somerset in southwestern England, said he was hoping: "She's going to pull some rabbit out of the hat to make up for the fact that actually she doesn't appear to be listening to what an awful lot of the members of the party are saying.

"I feel sorry for her, but I'm not sure feeling sorry for your prime minister is a good place to be," he said, as he stood near the front of a long queue to get into the main hall where May will speak.

She will try to address her party's fears of what some see as a growing threat from the main opposition Labour Party, which staged an upbeat conference last week when its leaders voiced confidence of winning any new election.

Taking aim at Labour's leader, Jeremy Corbyn, she will say that millions of people are "appalled" by his leftist policies, which include renationalising rail, mail and utilities and boosting spending on infrastructure and housing.

"They want to support a party that is decent, moderate and patriotic. One that puts the national interest first," she will say. "We must show everyone in this country that we are that party."

But it will be her words on Brexit that most will focus on.

With no agreement with the bloc over the divorce or a future relationship, the last day of the conference marks the beginning of what some officials predict will be a frenzied couple of weeks of diplomacy between London and Brussels as the two sides try to secure a deal to end more than 40 years of partnership.

May and her team face weeks of difficult conversations with Brussels to win a deal, but she also faces challenges from inside her own party and from her partners in parliament, Northern Ireland's Democratic Unionist Party.

DUP leader Arlene Foster has used the conference to loudly set out her red lines for Brexit, repeating that she will not accept a border between Northern Ireland and the rest of the United Kingdom. "The red line is blood red," she told the BBC.

Describing Britain's divorce as a "moment of opportunity", May will promise to always act in the "national interest", a swipe at Johnson, whose alternative proposals for leaving the EU, she says, would tear the United Kingdom apart. 

(With inputs from agencies.)