When 'off the record' becomes on the agenda as 'swivel-eyed loons' furore grows

The journalists had barely begun their dinner on Wednesday evening – ribs and rare breed lamb at the Blue Boar Smokehouse in the InterContinental hotel a short walk from the House of Commons – when a senior figure close to the Prime Minister passed by their table.

A couple of hours earlier, 114 Tory MPs had voted against the Queen's Speech in protest over an EU referendum. The discussion reportedly ended with an extraordinary attack on the "mad, swivel-eyed loons" in the grassroots of the party who had forced the backbenchers to rebel against the Government.

Lord Feldman denies it is he who said those words, and the newspapers, who didn't name him, stand by their story. But the incident itself is shrouded in the concept of "off the record". Off the record is criticised by some because it allows attacks to be made without accountability. Yet to most reporters, it is an essential part of freedom of speech – it affords anonymity to sources to expose wrongdoing and question those in power without fear of recrimination. Political journalists use "lobby rules" whereby private conversations – including those over lunch – are honoured by the off-the-record agreement.

Ten years ago this week, Peter Mandelson made disobliging remarks about Gordon Brown and Tony Blair at a lunch with women journalists. The lunch was private, and the comments were reported – without the source being named. Yet with 18 journalists present, his identity leaked out, triggering a huge row. Could Lord Mandelson have reasonably expected his comments to remain private with so many journalists present?

The Blue Boar encounter falls into a similar grey area where off the record is blurred: the speaker was passing by, not eating with the journalists, but the conversation was still seen as private. Did they have a reasonable expectation of privacy? Should they have been so (allegedly) loose-lipped?