YESTERDAY, 23 MPs across the political parties laid before the House of Commons a motion calling for a select committee to examine the case for impeaching the Prime Minister for his conduct over the war in Iraq.
The last time such proceedings were brought successfully was in 1806, against the "uncrowned King of Scotland", Henry Dundas, 1st Viscount Melville, although it was his behaviour at the Admiralty rather than in Scotland which was under examination.
Melville was acquitted, which serves as a reminder that impeachment is a parliamentary process of examination and accountability rather than, in itself, a verdict.
The key question is whether the Prime Minister has a case to answer.
In a carefully argued paper ( www.impeachBlair.net , prepared for MPs, academics Dan Plesch and Glen Rangwala document 28 instances where the Prime Minister’s public statements are apparently at variance with the information that he had then received from the intelligence services.
Much of the information we have now can be found in the evidence to the two inquiries set up by the Prime Minister, Hutton and Butler. Within the evidence now published lies the information that makes the case against the Prime Minister’s conduct.
This is not just a matter of Parliament being misled - as we know now it was. There were no weapons of mass destruction in Iraq. This is also an issue of whether the Prime Minister was in a position to know that his statements were wrong.
I offer just one example of the mass of evidence which can now be deployed. On 17 September 2002 the Prime Minister’s own Chief of Staff - Jonathan Powell - wrote in an e-mail that the government "will need to make it clear that we do not claim that we have evidence that he [Saddam] is an imminent threat".
And yet when he presented that very case to the House of Commons one week later, Tony Blair claimed "the threat is serious and current".
Perhaps the Prime Minister can explain these and the other 27 discrepancies. However, there is a case to answer.
No self-respecting parliament can accept a position where its decisions are reached on the basis of misinformation. All standard parliamentary procedures for holding the government to account have been exhausted and found wanting. It is into this vacuum that impeachment comes back as the final protection of Parliament, and thus democracy itself.
There is no more important issue than the question of peace or war. There is no more important bulwark of democracy than the ability of the legislature to hold the executive to account.
In reviving the process of impeachment, 23 MPs from across the political spectrum have planted our flag in the ground. We shall see now how many others rally to that standard.
Alex Salmond, MP, is the leader of the Scottish National Party.