Some of the protesters were dressed as orang-utans
About 50 Greenpeace campaigners, some dressed as apes, have staged a protest at two Unilever sites over the company's use of palm oil.
The protesters went into the plant at Port Sunlight, Wirral, and Unilever House, London, early on Monday.
Campaigners left both sites about nine hours later after talks with managers.
Greenpeace claims the use of palm oil is damaging the Indonesian rainforest, but Unilever says it is leading the search for a sustainable product.
In November, the Roundtable on Sustainable Palm Oil (RSPO) - which Unilever chairs - agreed criteria for sustainable palm oil production which addresses many of Greenpeace's concerns, the company said.
"The problem is simply that demand of palm oil has exploded," a spokesperson said.
"It is essential that all those involved sign up to agreed criteria to make sustainability work on the ground - but this is not an easy process and is taking longer than we would all like.
It was a frank exchange of views but very amicable and grown up
"Nevertheless, we remain absolutely committed to finding a solution."
A spokeswoman for Merseyside Police said officers monitored the protesters during the demonstration, which she described as "peaceful".
A Greenpeace spokesman said the group arrived in two vans at the front and back entrance of the Wirral site at about 0640 BST and simply walked in.
Later at 0735 BST, campaigners dressed as orang-utans scaled ladders on to a balcony at the headquarters in London.
Campaigners left both sites at about 1545 BST after a meeting with a senior Unilever manager from London.
Andy Tait, a campaign manager for Greenpeace at the Wirral protest site, said: "Unilever have promised a substantive response in the next couple of weeks and during that time we will look at other ways to keep up the pressure.
"Today has been a success in terms of keeping it on the public's and Unilever's agenda but the real success will be when Unilever changes their policies by not dealing with suppliers who destroy the rainforest."
A Unilever spokesman said production at the plant in the Wirral had not been affected by the action.
"It was all very peaceful and amicable," said the spokesman.
"One of our senior managers in London met with a Greenpeace representative today. It was a frank exchange of views but very amicable and grown up."
Greenpeace is urging Unilever to use its influence to stop palm oil suppliers clearing areas of rainforest - the natural habitat of orang-utans in Indonesia - to support the crop.
Palm oil is an ingredient in foods, soaps and detergents and a bio-fuel added to diesel for cars.
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