LONDON, Oct 4: British Prime Minister Gordon Brown marked his 100th day in office on Thursday facing possibly the biggest decision of his career: whether to call snap elections in a make-or-break political gamble.

Speculation has reached fever pitch that Brown could announce early polls next week in a bid to capitalise on an unexpected surge in his popularity since he succeeded Tony Blair in June.

If he calls elections and wins, he could stay in Downing Street until at least 2012, with his own mandate; if he loses, he could go down as the second shortest-serving prime minister in British history.

“An election is still Mr Brown’s to lose,” wrote Camilla Cavendish in the Times newspaper, referring to the widespread belief that Brown should win a snap election, given buoyant recent poll ratings.

“But he is looking more vulnerable than he could have imagined two weeks ago,” she added.

David Cameron, leader of the main opposition Conservatives, piled the pressure on Brown on Wednesday, challenging him to “go ahead and call that election” in a showpiece speech at the end of his party’s annual conference.—AFP