Michael Jackson is widely expected to announce details about his pop comeback at a press conference in London later.

Jackson will make a “special announcement” at the O2 Arena this afternoon (March 5th).

The singer is believed to have agreed to stage a greatest hits residency which could see he perform up to 30 shows at the venue.

If confirmed, Jackson's concerts will be one of the most anticipated events of the 21st century.

The singer arrived in the capital by private jet from Los Angeles on Tuesday (March 3rd), and hysteria has been building outside his hotel in West London ever since.

Yesterday (March 4th), a Michael Jackson impersonator entertained photographers and members of the press with a routine of some of the singer's legendary dance moves.

Jackson has not performed a full concert since he was cleared of child molestation charges in 2005. His last full tour, entitled HIStory, took place in 1996 and '97.

He is thought to have agreed to perform in London because his music is still popular across much of Europe.

Speculation about Jackson's future as a performer increased in January when his spokesman said the singer had returned to Los Angeles in order to relaunch his career.

Despite reports about the singer's supposed bad health, Jackson's spokesman, Tohme Tohme, said "the second half (of Jackson's career) will be better than the first."

(by Jason Gregory)