The Sun has formally backed the Conservatives at the General Election while its sister paper in Scotland has thrown its support behind the SNP.
In a nod to the imminent arrival of a royal baby, the front page of the Sun showed Mr Cameron's face on a swaddled newborn under the headline "It's a Tory" - and said only his party could keep the economy on track, "stop the SNP running the country" and guarantee an EU referendum.
Meanwhile The Scottish Sun went with a Star Wars motif, with SNP leader Nicola Sturgeon mocked up as a light sabre-wielding Princess Leia under the headline "Stur Wars", saying she would "fight harder for Scotland's interests at Westminster, offering a new hope for our country".
Defending the apparently contradictory approaches, a Sun spokesman said: "The Sun is written first and foremost for its readers, and the UK edition and Scottish edition have two very distinct audiences.
"If Scotland and England were playing each other at football, no one would expect The Scottish Sun to support the English national team."
The Sun backed the Tories in 2010 - after supporting Tony Blair in the previous three general elections - and while The Scottish Sun did not back either side in the referendum debate last year, it supported the SNP at the 2011 Scottish parliament election.