At Westminster there are often times when a politician says something and you only realise the significance of it much later.
In March 2006 Tony Blair said that Sir Swinton Thomas, the splendidly named interception of communications commissioner, wanted to tear up the Wilson doctrine about bugging MPs.
Now we all knew that Blair was someone with a) no great respect for the civil liberties lobby; b) a fairly sceptical attitude towards the prerogatives of MPs; and c) a tendency to take the advice of the intelligence services.
But Blair told parliament he was rejecting Sir Swinton's advice. It should have been obvious that something was up.
It was. Nick Robinson seems to have got to the bottom of it and there's an excellent account in his blog here. Briefly, he says that if the government scrapped the convention, they would have had to come clean about all the bugging of MPs that was going on in Northern Ireland.
Gerry Adams was first elected an MP in 1983 and it would not have been a surprise to anyone to learn that his phone had been bugged. But Robinson hints that other Northern Ireland MPs may have been under surveillance too. Tony Benn told me yesterday that the Wilson doctrine was an illusion. Nick Robinson seems to have confirmed that Benn was spot on.
This will not have been a surprise to anyone who saw Michael Cockerell's documentary about the foreign office a few years ago. Cockerell asked Robin Cook whether it was true that we spied on our EU partners to learn more about their negotiating tactics.
The usually unflappable Cook went as pink as a lobster and refused to answer. I can't remember Cockerell's words, but they were along the lines of: "We'll take that as a yes."
