The News of the World is backing the Conservatives in the general election, after 13 years of Labour support.
Britain's best-selling Sunday newspaper said in its leader column, the Tories offered the best hope for a "brighter, saner, safer, more honourable future".
It said its decision to switch parties followed "much soul-searching".
Last September, its sister paper, the Sun, also said it was turning its back on Labour, saying it had "lost its way and now it has lost us too".
'Fresh vigour'The News of the World said the country was crying out for change and Tory leader David Cameron must by given the chance to rule.
"We certainly do not deserve a headlong return to the days of Old Labour, of division, strikes and lost opportunity," it said.
"This paper backed New Labour to rid the nation of such a blight. Now, confronted with a renewed threat from old ways, the modernised Tories can be a force for good.
"It is time to give change a chance and move forward with fresh vigour and hope."
It added that Mr Cameron still had much to spell out and prove.
