The president of the European Parliament has criticised the controversial Anti-Counterfeiting Trade Agreement (Acta).
On German television network ARD, Martin Schulz said of the treaty: "I don't find it good in its current form."
His comments followed mass protests across Europe against the agreement.
Demonstrations took place at the weekend in various countries including Germany, Poland and the UK.
Mr Schulz said that the balance between copyright protection and the individual rights of internet users "is only very inadequately anchored in this agreement".
Supporters of the agreement insist it will not create new laws and is necessary to standardise copyright protection measures.
Acta is set to be debated in the European Parliament in June.
Although countries can individually enforce the agreement, the EU will need to play a role if the treaty is to be effective in enforcing intellectual property protection across several countries.
So far, it has been signed by 22 EU member states, including the UK.
However, Germany has held off from backing the agreement, citing the need for "further discussion".
Polish prime minister Donald Tusk said his country would wait for "sufficient consultation" before ratifying, following huge protests and disruption to several government websites.
Earlier this month, Slovenia's ambassador to Japan, Helena Drnovsek Zorko, apologised for her "carelessness" in signing the treaty on behalf of her country.
Mr Schulz's comments are a sign that Acta is in "real political trouble", according to Loz Kaye, leader of the Pirate Party UK.
"One of the things that's very interesting is that now the Acta agreement is coming under fire from all sides," he told the BBC.
"It's becoming clear that European citizens are very concerned about this agreement. It's hard to find anyone who is standing up for it right now."
A spokesperson for the International Trademark Association told the BBC that Acta offers a chance for the EU to "thwart" the problem of counterfeit goods.
"Acta is aimed at counterfeiters and pirates involved with commercial scale activities on the Internet, not the general user," a spokeswoman said.
"Too many criminals profit from selling counterfeit goods on the Internet at the expense of consumers' health and safety.
"The trade agreement is an opportunity for EU officials to help thwart this problem, and they can do so by adopting Acta and joining the international battle against counterfeiting."