By Elizabeth Piper and William James
BRIGHTON, England (Reuters) - Britain's main opposition Labour Party is ready for government, its leader Jeremy Corbyn will say on Wednesday, calling on Prime Minister Theresa May to end her government's "Brexit bungling", give up power and make way for his negotiators.
Corbyn is keen to press home his advantage over May, who is struggling to unite her party over Britain's negotiations to leave the European Union and to keep her own position, under threat from some in the party who cannot forgive the loss of their parliamentary majority in a June election she called.
At the end of an upbeat four-day conference which cemented leftist Corbyn's control over the party, the Labour leader will say the June vote had made his team of top advisers "a government-in-waiting".
With Labour closing the gap in opinion polls to stand roughly level with the Conservatives, the party is within sight of winning an election - although the governing party has said it has no plans to call a vote anytime before 2022.
"Against all predictions, in June we won the largest increase in the Labour vote since 1945 and achieved Labour's best vote for a generation. It's a result which has put the Tories (Conservatives) on notice and Labour on the threshold of power," Corbyn will say, according to excerpts of his speech.
"Yes, we didn't do quite well enough and we remain in opposition for now. But we have become a government-in-waiting. And our message to the country could not be clearer: Labour is ready."
So far, there is little appetite in the Conservative Party to hold an early election, and no clear frontrunner to replace May. Most do not want to open the way for Corbyn, whose promises to end austerity have won over many voters, particularly the young.
But a Labour spokesman said ahead of the speech that "the possibility of an early election is significant", and Corbyn's advisers were working out how to realize their policies.
"Things that we're talking about which were regarded as outlandish or somehow extreme when we first laid them out ... actually reflect the majority opinion in this country."
Promising to "genuinely" place power in the hands of the people and "do politics differently", Corbyn will criticize May's Brexit strategy, saying her Conservatives "are more interested in posturing for personal advantage than in getting the best deal for Britain".
"So I have a simple message to the cabinet: for Britain's sake, pull yourself together or make way."
(Editing by Mark Heinrich)