By Dominic Casciani
BBC News community affairs
Chinese President Hu Jintao is arriving in Britain amid tight security for a three-day state visit which includes banquets, trade talks and cultural events.
1999: Controversial police tactics
However, opponents of the Chinese government's human rights record are pledging to dog Mr Hu's trip, beginning with a vigil outside Buckingham Palace itself.
During the 1999 visit of Jiang Zemin, Mr Hu's predecessor, police confiscated pro-democracy banners and Tibet flags.
Some accused officers of using vans to shield the presidential motorcade from their protests.
Alison Reynolds, director of the Free Tibet Campaign, said they hoped to mount lively but peaceful protests - and said the test would be the police's response.
"We've had confirmation [from the police] that things will be different this time," said Ms Reynolds.
"Last time, the Chinese government rode roughshod over our freedoms - it's up to the British establishment to uphold these values.
"Chinese leaders should not be afraid of protests - just as they should not be afraid of the building of civil society at home."
Dalha Tsering of the Tibetan Community in Britain group said protesters would focus on Mr Hu's role in declaring martial law in the territory while he was party secretary there in 1989.
"He should be arrested and tried for his crimes, and yet he is drinking wine with the Queen and Tony Blair," said Mr Tsering.
"He is the tyrant of Tibet, and the world serenades him with business deals. Hu still has the blood of my countrymen on his hands, and yet world politicians seem unwilling to seek justice on our behalf."
Mr Tsering urged the government to encourage China to meet the Dalai Lama, the spiritual leader for most Tibetans who heads a government-in-exile in India.
Guihua Li, a pro-democracy campaigner, said that a coalition of Chinese people opposed to the Communist Party would also be protesting and had already handed an 8,000 name petition to Downing Street.
"Hu Jintao must immediately stop political persecution," said Dr Li. "Tony Blair must raise human rights violations directly. We have had 5,000 years of Chinese history - 56 years of Communist Party rule is too long."
Dr Li said followers of the Falun Gong spiritual movement would also demonstrate. Beijing has banned the group and, according to human rights monitors, its members are subjected to persecution and arbitrary imprisonment.
Many others who had sought asylum in the UK were however too scared to publicly demonstrate, said Dr Li.
"Despite China's economic progress, political persecution has not stopped," she said.
"People in the West see China now somewhere they can do business. But the first priority must be human rights. Without the Chinese Communist Party, we could achieve so much more."
A spokesman for the Metropolitan Police confirmed there had been talks with protesters ahead of the state visit.
"There will be no blanket removal of banners," said the spokesman. "But there may be a situation whereby a banner is breaking the law or causing offence [by inciting violence or criminal behaviour, for instance].
"We've approached this as we would any other demonstration - it is a process of negotiation with those concerned."
On Monday, Prime Minister Tony Blair stressed demonstrators had a right to make their voices heard.
"People are perfectly entitled to wear Free Tibet T-shirts or anything else," he said. "We live in a free, democratic country. People are perfectly free to say whatever they want to say."