Controversial ad shows severely sick COVID-stricken Santa Claus. Parents are outraged.

United Kingdom health officials have apologized for a controversial advertisement depicting Santa Claus with a severe case of COVID-19 that outraged parents say could be terrifying for children.

The short ad, titled "The Gift," shows National Health Service staff and volunteers working to save an elderly man's life after he's wheeled into a hospital by paramedics and put on oxygen, the UK Daily Mail reports. Health care workers in full PPE work diligently to nurse the man back to health.

Eventually, the man makes a full recovery and at the end of the video a Christmas gift left for his nurses reveals it was old St. Nick who frontline health workers saved.

The video ends with a slogan, "Give back to those who've given everything."

The ad was put together by NHS Charities Together, a group representing and supporting the work of NHS' official charities. It was published as part of the Gifts That Give Back Campaign encouraging people to send gifts to NHS staff for Christmas this year.

"We're delighted to share our Christmas campaign and video, which has been made possible thanks to generous brand partners," the charity group said in a social media post. "We adore the ad and dedicate it to all NHS workers who've given everything to care and keep us safe."

"Hundreds of thousands of NHS staff will be working over Christmas and New Year," said NHS Charities Together CEO Ellie Norton. "The public has responded magnificently so far to our appeal, helping us raise over £150million. But with the ongoing impact of COVID, the need is still there."

While some members of the public received the ad well, with the Daily Mail referring to it as "emotional" and "touching," others on social media slammed it as harmful to children's' mental health.

NHS Charities Together on Dec. 12 issued a statement in response to the negative feedback, clarifying that the ad was not targeted at children.

The charity said, "When we launched the ad earlier in the week, we had an overwhelmingly positive response to it. Some subsequent media coverage of it has generated criticism of the ad on social media and some people have expressed their concern about it upsetting children. The ad has been made to engage charity supporters and those who may want to buy products that generate donations to the appeal. It isn't aimed at children and hasn't been shown on TV. We are sorry to the parents of any young children who have been upset by watching the ad and to the young children themselves, they were not the intended audience for it."

The ad was subsequently pulled down from YouTube, Business Insider reported.