Britain's parliament votes today on contentious anti-terrorism laws in a test of Prime Minister Tony Blair's authority over his Labour Party ahead of an expected May election.
Opponents say the proposals - under which ministers will have powers to put suspects under house arrest without trial - violate basic freedoms that have underpinned Britain's judicial system for 800 years.
Some 30 Labour members opposed the bill last week and more abstained, raising the prospect of another revolt in the House of Commons today unless Mr Blair agrees to greater judicial scrutiny.
Labour's large Commons majority should ensure the bill's passage - although a sizeable rebellion would prove embarrassing. But the bill faces a tougher challenge in coming days in the House of Lords, the unelected upper chamber where Labour lacks a majority.
The Lords cannot reject legislation but they can delay it, preventing the bill from becoming law before the expected election.
Despite that, Mr Blair shows little sign of meeting his critics' main demand of giving judges the first say on house arrest orders. That power must remain with the government to protect Britain from a "serious security threat," he says.