LONDON (Reuters) - Green groups have formed a coalition against three high-profile London 2012 sponsors, the latest in a wave of protests that have heightened fears that demonstrators are ramping up their campaigns in the run-up to the Games in nearly 100 days' time.
The coalition, which launched the campaign "Greenwash Gold 2102" on Monday, argues that Dow Chemical, oil company BP and mining giant Rio Tinto should not be involved in the Olympics because of their environmental records.
The campaign, which includes activist groups the Bhopal Medical Appeal and UK Tar Sands Network, is one of a collection of protests ranging from local communities fighting construction of venues in their neighbourhood to trade unions complaining about work conditions.
Protests have been peaceful, but police and Olympic chiefs are aware the Games, and torch relay, could be a magnet for demonstrators keen to publicise their message at a time when the world's attention will be on London.
Police last month warned that attention-seekers rather than the violent protesters who marred the torch relay four years ago will pose the biggest threat.
Earlier this month, a lone protester disrupted the traditional university boat race between Oxford and Cambridge, forcing a restart.
Authorities have so far taken a softly, softly approach, with the aim of deterring copycat behaviour, saying protesters have the right to demonstrate peacefully.
But they warn they will clamp down on anyone attempting to disrupt events.
London Olympic organisers (LOCOG) said it had planned for any disturbances, adding it was "confident that any protests will be handled in a sensible and appropriate way".
The most high-profile protest so far has been Bhopal Medical Appeal's campaign against Dow Chemical's sponsorship of the wrap, strips of plastic decorating the outside of the main stadium.
BMA says the seven million pound sponsorship should be dropped because of Dow's link to the 1984 Bhopal gas disaster in India, in which activists say 25,000 people died in the years that followed.
Peaceful demonstrations have been held, and some lawmakers in both Britain and India have backed the campaign.
Another protest catching the headlines this month was a hoax press release and web page by the Campaign for a Sustainable Olympics which falsely claimed LOCOG had dropped BP as a sustainability partner.
The group, complaining at BP's role in the Deepwater Horizon oil spill in the Gulf of Mexico and its work in the controversial Canadian tar sands, fooled a couple of news outlets which published the story.
Other demonstrations have seen London Occupy activists join forces with locals in an attempt to halt the building of temporary basketball training courts near the Olympic Park, arguing the development had been pushed through without proper consultation and an environmental impact assessment.
Four people were arrested when bailiffs moved in last week to enforce an eviction order.
The TUC-backed Playfair, which campaigns against what they say are poor working conditions and low pay in factories where 2012 merchandise is made, will hold a series of demonstrations in the next week in several British cities.
In a separate move, a local campaign called the Counter Olympics Network is planning "major actions".
The launch of Greenwash Gold 2012 was chaired by Meredith Alexander, who in January resigned from the body overseeing the environmental and ethical impact of the London Olympics in protest at Dow's sponsorship.
"There is an expensive machine behind the Games that is funded by corporate sponsors," she said in a statement.
"Sadly when these sponsors are selected, money talks much more loudly than values."
Rio Tinto, which will provide the metals for the 4,700 medals, said; "We run our business to very high ethical standards and are committed to human rights and running our mines responsibly.
"A commitment to the environment and sustainable development is ingrained in the Olympic charter."
Dow, which denies any responsibility for the accident at the then Union Carbide India Limited factory, said in an interview with Reuters earlier this year that it would not be deterred by protests.
BP said it "remained committed to help LOCOG deliver a more sustainable Games".
Reporting by Avril Ormsby; editing by Martyn Herman