Websites hosting pirated music or films could be blocked by the authorities, after the government reintroduced the measure to the Digital Economy Bill.

The plans, if approved, would allow ministers to permit injunctions that block websites illegally offering a “substantial amount” of material that is under copyright. But it would need to be demonstrated that any blocked site has a “serious adverse effect on businesses or consumers”.

The aim of the move is to protect the revenues of content owners and creators, but the proposed blocking of sites has been met by strong protests in the interests of freedom of speech. The government has also been accused of attempting to secretly rush through the legislation before this spring’s general election.

The change, if approved, would take place without primary legislation and would follow a public consultation. It is expected that the move would allow ministers the final say on any website being blocked.

The Conservatives and Liberal Democrats had blocked the government’s prior attempts to modify the Copyrights, Designs and Patents Act, forcing this change of approach.

A Conservative spokesperson told the Financial Times that the party supports the newly-proposed changes. But the Liberal Democrats have objected to the change, the Guardian reported, insisting the Bill needed to wait for the next parliament instead of quick changes being made.

The Open Rights Group, which campaigns for digital rights, said today on its blog that it was asking supporters for donations for a newspaper advertising campaign. The advertisements will argue against the Bill, and will feature on Tuesday, when parliament debates the changes.