David Cameron and Chris Bryant's ongoing dispute is continuing by the medium of letter, after the prime minister issued a catty response to Labour's questions around the Leveson inquiry.
This Wednesday, Cameron specifically refused to answer any Commons questions from Bryant unless he apologised for suggesting he was a liar earlier in the year. That refusal prompted shadow media secretary Harriet Harman to write to the prime minister to ask the same question as her colleague.
"Chris Bryant made a point of order in the House in which he suggested that I had misled the House," the prime minister wrote back today.
"The information he used was inaccurate and therefore the suggestion that I had misled the House was not correct.
"Chris Bryant has apologised to Lord Justice Leveson for his actions and he has apologised to the House for misleading it. However, he has not yet apologised to me," he wrote.
Cameron then writes a wry paragraph in which he claims to be happy to answer Harman's questions, while offering no new information at all.
"I am, however, happy to respond to your questions in full," he wrote.
"As you know, I set up the Leveson Inquiry. I have co-operated fully with the Inquiry and given them all the material that they have asked for."
While the catty and sarcastic tone of the letter will amuse parliamentary observers, the final line sees Cameron put on paper his assurance that he has passed on all the correspondence between himself and former News International chief executive Rebekah Brooks.
That specifically contradicts several media reports which claim much of their correspondence has not been handed to the Leveson inquiry.