WASHINGTON, April 1, 2008 (AFP) - US lawmakers moved Tuesday to prohibit US President George W. Bush from attending the Beijing Olympics opening ceremony, amid a global uproar over China's crackdown in Tibet.

A bill was introduced in the House of Representatives by lawmaker Thaddeus McCotter, chairman of the House policy committee of Bush's own Republican party, compelling the US leader to skip the ceremony.

In addition, 15 lawmakers from both the Republican and Democratic parties asked Bush in a letter to 'renounce your decision to attend the Olympics in China and urge the Chinese government to change its policies and begin to respect international standards of human rights.'

The bill wanted 'to prohibit federal government officials and employees' from attending the opening session of the Beijing Olympics based upon China's 'brutalizing protesters in Tibet.'

'Given what is happening to the people of Tibet, it would be a careless sign of the president of the United States to attend those games,' McCotter told AFP.

'President Bush, as the leader of the Free World, must uphold America's beacon of liberty to the world's oppressed. This noble cause is harmed through his attendance as a guest of this oppressive communist government, he said.

He expected lawmakers from both sides of the aisle to back the bill, which Bush could still veto under his powers.

'I think more that anything, the president will see how serious members of Congress view this situation,' McCotter said.

The US leader has said he plans to attend the Olympic Games in August despite calls for world leaders to boycott the ceremony in protest at the Chinese government's crackdown on demonstrations against its rule in Tibet.

German Chancellor Angela Merkel has said she will not attend the ceremony, and French President Nicolas Sarkozy has not ruled out following suit.

Exiled Tibetan leaders have put the death toll from the Chinese crackdown at 135-140 people, with another 1,000 injured and many detained following protests that began in the Tibetan capital Lhasa on March 10 and escalated into rioting there four days later.

China says Tibetan rioters killed 18 civilians and two police officers.

House of Representatives Speaker Nancy Pelosi, the top US Democratic lawmaker, also Tuesday urged Bush to consider skipping the opening ceremony.

'I think boycotting the opening ceremony, which really gives respect to the Chinese government, is something that should be kept on the table,' Pelosi told ABC television in an interview.

During a visit to India in March, Pelosi made the first high-level call on the Dalai Lama, the exiled Tibetan spiritual leader, after the protests.

T. Kumar, Amnesty International's Washington-based Asia-Pacific advocacy director, said if Bush wanted to still proceed with his trip to Beijing, he should also visit Tibet 'to see for himself the human rights situation' in the Himalayan territory.

Bush should also push for a UN probe into the Tibetan crisis, Kumar said.

With just over four months until the opening ceremony, Amnesty warned in a report Tuesday that it was increasingly unlikely the games would improve rights in China and urged the International Olympic Committee (IOC) and world leaders to speak out publicly against rights violations.

Bush has already raised concerns over the bloody turmoil in Tibet with China's President Hu Jintao, seeking restraint and calling for the resumption of talks between Beijing and representatives of the Dalai Lama.

The bill introduced Tuesday was the first legislation proposed in Congress since the Chinese crackdown in Tibet.

It also was to rebuke Beijing for 'supporting and enabling Sudan's genocidal regime, curtailing religious and labor rights, allowing environmental degradation and 'systematically denying the Chinese people their basic freedoms.'

There are already two non-binding resolutions proposed in the House of Representatives calling for a total US boycott of the Beijing Olympics which are unlikely to be passed.