Former News of the World chief reporter Neville Thurlbeck has accused Tom Watson of using his parliamentary role "as a subterfuge for gleaning information for his book".
In a blog expanding on criticism he made for reporting "off-the-record" comments, Thurlbeck wrote that Watson had reported a private correspondance between the two in his book, Dial M for Murdoch, in which the Labour MP revealed he and his fellow colleagues on parliament's culture committee had been put under "covert surveillance".
"I’m not remotely angry with Tom Watson, I simply want to set the record straight. If anything, I’m just irritated that he can’t seem to hold a confidence when he is meant to be probing serious wrong doing," Thurlbeck wrote.
Thurlbeck also said News of the World journalists had "grave reservations" about carrying out surveillance on MPs, stressing that decisions were taken by News International executives, over the head of editor Colin Myler and without Rebekah Brooks' knowledge.
"For the record, every one of my colleagues had grave reservations about carrying out the surveillance… It wasn’t journalism. It was corporate espionage."
Watson said on Saturday he would fully respond to Thurlbeck's comments soon.