LONDON — London Mayor Boris Johnson says he'll stand for Parliament in next year's general election — putting him into a position to ultimately challenge Prime Minister David Cameron for the Conservative Party's leadership.

The off-the-cuff announcement was made Wednesday in a question-and-answer session after a speech in London. It ends months of speculation as to the next step for the garrulous, floppy-haired leader, whose term ends in 2016.

Johnson says he hasn't identified a seat that he would like to seek, but that "since you can't do these things furtively, I might as well be absolutely clear — in all probability I will try to find somewhere to stand in 2015."

Johnson is a formidable campaigner whose presence adds a celebrity quality to the Conservative Party ticket.