HONG KONG (Reuters) - A Chinese state-backed newspaper on Friday defended a mainland student running for university office in Hong Kong against what it described as a dangerous "McCarthyite trend" in the former British colony.

The Global Times invoked the language of US Senator Joseph McCarthy's anti-Communist crusades of the 1950s to seek to protect Eugenia Yip, who is running for social secretary of the student union of the prestigious University of Hong Kong.

Yip has faced criticism from pro-democracy activists, who fear she is part of a broader effort to tighten Beijing control over the city, which returned to Chinese rule in 1997 with wide-ranging autonomy.

Communist Party leaders in Beijing declared two-and-a-half months of student-led street protests in Hong Kong against perceived Chinese meddling as illegal.

Yip, a business student, has spoken openly of her former membership of the party's Youth League, which is widely seen as a training ground for eventual full party membership. "Hong Kong University must not let McCarthy enter the gates," the Global Times warned in a commentary.

It said the student had been a victim of "vicious attacks from the outside" that claimed she was a "pawn" in the Communist Party's infiltration of the university.

The article noted that as part of the broader trend of integration between mainland and Hong Kong universities, many mainland students would be members of the league.

"To suspect that they are so-called pawns shows too much imagination," the article said. "If Hong Kong society does not work together to prevent this McCarthyite unhealthy trend towards mainland students, then that could accelerate Hong Kong hitting rock bottom."

Yip told Reuters that she did not have a relationship with the party and had quit the league before heading to study in Hong Kong. "It's very, very common for my class, at least at my school," she said.

She warned about poor communication and understanding between mainland students and their Hong Kong peers.

The article comes amid local fears of a looming campaign by pro-Beijing forces against the university, which is home to various pro-democratic activists.

The former dean of its law school, Johannes Chan, this month complained of a Cultural Revolution-style smear campaign against him in pro-Beijing newspapers to scupper his chances of a promotion to a key administrative post.

Hong Kong leader Leung Chun Ying used his annual policy address to criticise a little-known student publication that had commentaries debating Hong Kong nationalism and independence.