FACTBOX: Five facts about Spain's Mariano Rajoy

(Reuters) - Following are key facts about Mariano Rajoy, leader of Spain's main opposition conservative Popular Party, who is challenging for power in Sunday's election:

-- Rajoy, a former deputy prime minister and interior minister in the government of Jose Maria Aznar, has been a relentless critic of the Socialist government, and especially of its attempt to negotiate with Basque rebels.

-- Rajoy was hand-picked by former prime minister Jose Maria Aznar to succeed him as party leader in 2003.

-- Rajoy seemed on course to become prime minister until Islamists bombed Madrid trains three days before the election in March 2004, helping bring a surprise victory to the Socialists.

-- He has surprised many by making immigration one of the top issues for the first time in a Spanish election, calling for an immigration points system and restrictions on the Islamic headscarf.

-- Rajoy, 52, hails from Spain's rainy northwest. He is married, with two children, and is fond of football and cigars.

(Reporting by Elisabeth O'Leary; Editing by Kevin Liffey)