Mary Cheney, the openly gay daughter of US Vice-President Dick Cheney and wife Lynne, is pregnant, according to a published report.

Mary Cheney, 37, and her partner of 15 years, Heather Poe, 45, are "ecstatic" about the baby, due in late spring, The Washington Post reported in yesterday's editions, quoting an unnamed source close to the couple.

The vice-president's older daughter, Elizabeth Cheney, is on leave as deputy assistant secretary of state in advance of having her fifth child with her husband in July.

There was no formal announcement of either daughter's pregnancy from the vice-president's office, but the Post quoted spokeswoman Lea Anne McBride as saying Tuesday night that "the vice-president and Mrs Cheney are looking forward with eager anticipation to the arrival of their sixth grandchild."

Mary, 37, was an aide to her father during the 2004 campaign, as was Elizabeth, and now is vice- president for consumer advocacy at AOL.

The Post quoted the source close to the family as saying the circumstances of Mary Cheney's pregnancy will remain private. She and Poe moved from Colorado to Virginia a year ago to be closer to the Cheney family.

In an interview with the Post six months ago, when asked if she and Poe wanted children, Cheney said that was a "conversation I think I should have with Heather first."

According to Washington Post's report, news of the pregnancy will undoubtedly reignite the debate about gay marriage.

During the 2004 campaign, Mary Cheney was criticized by gay activists for not being more publicly supportive of same-sex marriage.

Her father said people "ought to be free to enter into any kind of relationship they want to" but deferred to the president's policy supporting a constitutional amendment banning same-sex marriages.

Cheney herself called the proposed amendment "a gross affront to gays and lesbians everywhere" in her book, "Now It's My Turn: A Daughter's Chronicle of Political Life," which was published in May.

Cheney has described her relationship with Poe whom she took to last year's White House dinner honouring Prince Charles and Camilla as a marriage.

The two met in 1988 while playing ice hockey and began dating four years later.

In November, Virginia voters passed a state constitutional amendment banning gay marriage and civil unions; state law is unclear on whether Poe could have full legal rights as a parent of Cheney's child.

Source: China Daily