The Vice President of the United States has told CNN that he is delighted about the imminent birth of his sixth grandchild, and told presenter Wolf Blitzer he was out of order for bringing it up.

Mr Cheney was piqued that the TV host chose to mention the pregnancy of his younger daughter Mary in the context of criticism from fundamentalist groups who think it is wrong for a lesbian to have a child.

Ms Cheney, 37, announced in December 2006 that she is pregnant. She has been with her partner Heather Poe for 15 years.

The Vice President has always been publicly supportive and protective of his younger child, who played a key role on his campaigns for the second-highest office in the land in 2000 and 2004.

Interviewed on CNN’s Situation Room, Mr Cheney was congratulated on the upcoming birth by presenter Wolf Blitzer, who then went on to read out a statement from pressure group Focus on the Family.

“Mary Cheney’s pregnancy raises the question of what’s best for children.

“Just because it’s possible to conceive a child outside of the relationship of a married mother and father, doesn’t mean it’s best for the child.”

Mr Cheney, who will be 66 at the end of this month, was visibly displeased at the attempt to paint his child as a bad role model.

He replied, “I’m delighted. I’m delighted I’m about to have a sixth grandchild, Wolf, and obviously think the world of both of my daughters and all of my grandchildren.”

Then he added “And I think, frankly, you’re out of line with that question.”

The presenter hastily attempted to mollify Mr Cheney, saying he felt the question was responsible and fair.

“I just fundamentally disagree with your perspective,” the Vice President replied.

When Presidential candidate John Kerry raised Mary Cheney’s sexual orientation during the 2004 campaign for the White House, her father was reportedly furious.

Mr Cheney has publicly stated that he did not think there was a need for federal intervention to ban same-sex marriages, and has often spoken publicly of his love, admiration and respect for his lesbian daughter.

Ms Cheney’s partner Heather Poe often appears with the Vice Presidential family at official and political functions and events.