Rupert Murdoch, Chairman of News Corporation, has spoken out in support of Republican presidential candidacy hopeful and marriage equality opponent Rick Santorum’s “big vision” for the US and praised his presentation style “regardless of policies”.

The billionaire, whose News Corp. owns Fox News, recently began using the micro-blogging site Twitter.

He wrote two messages ahead of the Iowa caucuses yesterday on Santorum, who has said he will support efforts to dissolve existing gay marriages if elected.

Murdoch wrote: “Good to see santorum surging in Iowa. Regardless of policies, all debates showed principles, consistency and humility like no other. [sic]”

He added: “Can’t resist this tweet, but all Iowans think about Rick Santorum. Only candidate with genuine big vision for country.”

News Corp., which is controlled through Murdoch family-owned shares with voting rights, prompted controversy in 2010 after donating $1 million to the Republican Governors Association ahead of the country’s midterm elections.

The Democrat Governors Association asked its subsidiary, Fox News, to “add a formal disclaimer to your coverage any time any of your programs covers governors or gubernatorial races between now and election day”.

Fox News has in the past denied a political bias to the right, and Murdoch used his Twitter account to promote conservative talkshow host Glenn Beck’s replacement, saying: “Got to watch Foxnews at 5 EST. Liberal Bob Beckel and team great replacement for Beck and much more fun.”

The editorially independent Times, which is owned by News International, a division of News Corp., described Hungary’s new constitution, which includes a constitutional ban on gay marriage similar to that proposed by Santorum as “an extraordinary affront to basic liberties” this week.

Santorum has emerged second-favourite in the Iowa caucuses after Mitt Romney having experienced a last-minute surge in support.

He has confirmed that if elected as president of the US, he would support a constitutional amendment invalidating the existing marriages of gay couples and has in the past blamed lower wedding rates in gay marriage.