The House of Lords has launched an almost universal attack on the government's 42-day detention plans in its first day of reading in the second chamber.
Peers had been widely expected to reject the proposals and send them back to the Commons, but yesterday speech after speech lambasting the arguments for increased detention gave some idea of the depth and breadth of opposition.
Perhaps the most significant message came from Lady Manningham-Buller, former head of MI5. Rumours had circulated in political circles ahead of the Commons vote suggesting the security services were lukewarm but supportive of the plans. Her categorical rejection of the government's actions, in her maiden speech in the Lords, provoked clear satisfaction from those around her.
"I've weighed up the balance between the right to life, the most important civil liberty, the fact that there's no such thing as complete security, and our hard won civil liberties," she said.
"And therefore on a matter of principle I cannot support 42 days pre-charge detention in this bill."
The former lord chancellor and Tony Blair's former flatmate Lord Falconer - who had voted for 90-day detention under Mr Blair's premiership - came out against the plans.
He cast doubt on the concessions offered by the government whereby parliament would authorise the extended detention on a case-by-case basis by comparing it, rather implicitly, to the manner in which the Commons vote had been won last month using Democratic Unionist party MPs.
"I find it worrying someone could be kept in prison on the basis of a deal done with another political party," he said.
"The safeguards are obviously defective but I will vote against the whole bill."
Shadow security minister Baroness Neville-Jones said: "At the heart of the debate is one central question: what type of society are we trying to create, protect and secure?
"After all, it is on the effects of our actions, not on our intentions - however virtuous these may be - that we will be judged.
"It represents yet another attempt on the part of the government to abridge without sufficient justification fundamental democratic rights and freedoms that have underpinned our society for centuries and which we have defended against tyranny on many occasions."
The Lords will almost certainly return the proposals to the Commons around autumn. There will then follow a protracted game of parliamentary ping-pong in which the bill bounces from house to house.
That stage of proceedings is fairly predictable - other than the variations in Commons votes when it returns. The most significant variable is whether Gordon Brown will dare to implement the Parliament Act to force the plans into law.
This option has been taken before - most notably over fox hunting - but to do so on a constitutional issue without cross-party support in the Commons could provoke consternation and outrage among large swathes of parliamentarians.