BEIJING (REUTERS) - A group of families demanding justice for the victims of China's 1989 Tiananmen Square crackdown have denounced new Chinese President Xi Jinping for failing to launch political reforms, saying he was taking China"backwards towards Maoist orthodoxy".

The Tiananmen Mothers activist group has long urged the Chinese leadership to open a dialogue and provide a reassessment of the June 4, 1989 pro-democracy movement, bloodily suppressed by the government which labelled it a "counter-revolutionary"event.

In an open letter released on Friday through New York-based Human Rights in China, the group said Mr Xi "has mixed together the things that were most unpopular and most in need of repudiation" during the time of former paramount leaders Mao Zedong and Deng Xiaoping, the latter who oversaw the putting down of the protests.

"This has caused those individuals who originally harboured hopes in him in carrying out political reform to fall into sudden disappointment and despair," the group said.

Mr Xi became Communist Party chief in November and president in March at a time of growing public pressure to launch long-stalled political reforms.

Some intellectuals had predicted that Mr Xi would follow in the footsteps of his father Xi Zhongxun, a reformist former vice-premier and parliament vice-chairman. Mr Xi has also tried to project a softer and more open image than his predecessor Hu Jintao.

But his government has clamped down on free expression on the Internet and detained anti-corruption activists, giving no sign that the party will ever brook dissent to its rule.

The Tiananmen Mothers said it has not seen Mr Xi "reflect upon or show remorse in the slightest for the sins committed during the three decades of Maoist communism".

"What we see, precisely, are giant steps backwards towards Maoist orthodoxy," the group said.

After initially tolerating the student-led demonstrations in the spring of 1989, the Communist Party sent troops to crush the protests on the night of June 3-4, killing hundreds.

The topic remains taboo in China and the leadership has rejected all calls to overturn its verdict.

A handful of people remain in prison, 24 years on, according to the Dui Hua Foundation, a US group that works for the release of Chinese political prisoners.

While China grapples with thousands of protests a year, over everything from pollution to corruption and illegal land grabs, none of these demonstrations have even come close to becoming a national movement that could threaten the party's rule.