HONG KONG, May 31, 2009 (AFP) - Hong Kong police have charged two men over a plot to assassinate one of the city's leading pro-democracy campaigners Martin Lee, a spokeswoman said Sunday.

The two men - aged 49 and 50 - were due to appear in court on June 16, the police spokeswoman told AFP.

The plot to kill Lee, a veteran activist and long-time critic of Beijing, was revealed on Saturday, but took place last summer during elections for Hong Kong's legislature.

The 70-year-old confirmed the plot Saturday, but said he had been asked by police to keep silent after the two men were first arrested last August.

The South China Morning Post revealed the story, saying police had arrested an alleged hitman from China and a Hong Kong accomplice.

The spokeswoman would not confirm where the two men were from.

She said the 49-year-old had been charged with conspiracy to shoot a person, carrying a firearm with intent, possession of a firearm and ammunition without a licence and conspiracy to commit grievous bodily harm.

The 50-year-old has been charged with possessing arms and ammunition without a licence.

Lee, who stepped down as a legislator last July, told reporters Saturday: "I was never afraid because, as a Catholic, death to me is just like pushing the door open to another life."

The plot was uncovered during the 2008 Legislative Council elections, one of the limited voting opportunities in the city.

Universal suffrage was promised to Hong Kong when it was handed back to China by colonial power Britain in 1997, but no timetable was set and democrats remain frustrated at the slow pace of constitutional reform.

As well as his pro-democracy stance, Lee has been at the forefront of the campaign to remember and vindicate pro-democracy activists who led a six-week protest in Tiananmen Square in Beijing in 1989.

The 20th anniversary of the crackdown on the protests - which left hundreds, possibly thousands, dead across the Chinese capital - will be marked on Thursday in Hong Kong with a candlelight vigil expected to draw tens of thousands.

Hong Kong, which has a separate legal system from China, has an outspoken and vibrant political culture, but violence against politicians is rare.