Culture Secretary Jeremy Hunt has asked media regulator Ofcom to review the practicalities of a planned clampdown on illegal file-sharing on the internet.
Powers to allow courts to block access to websites which infringe copyright on music, films and TV shows were included in the Digital Economy Act, which was passed by the previous Labour administration with the backing of creative industry bodies.
But campaigners for internet freedom argue that they could open the door to wider online censorship.
Mr Hunt said on Tuesday he had "no problem" with the principle of blocking access to sites which exist purely to allow illegal downloading.
But he said he wanted Ofcom to examine whether the planned powers were workable.
"The Government is committed to creating the right conditions for businesses to grow," he said. "That includes providing them with the right tools to protect the products of their hard work and investment.
"The Digital Economy Act seeks to protect our creative economy from online copyright infringement, which industry estimates costs them £400 million a year.
"I have no problem with the principle of blocking access to websites used exclusively for facilitating illegal downloading of content.
"But it is not clear whether the site-blocking provisions in the Act could work in practice so I have asked Ofcom to address this question.
"Before we consider introducing site-blocking we need to know whether these measures are possible."
