Satirist Armando Iannucci has hit back at Alastair Campbell after the pair's Twitter spat over the weekend.
Mr Campbell criticised the Thick Of It creator for accepting an OBE in Saturday's honours list.
Having rebuffed the attack online, Mr Iannucci expressed surprise that Tony Blair's former spin doctor was so worked up over the matter in a Q&A session with political journalists in parliament.
"I don't know what his isotope is, but he has a half-life of 300 years," he said at the event promoting his new American comedy, Veep, last night.
"I just woke up on Saturday morning and just for a bit of fun tweeted twice. He's still going. My mum rang me on Sunday really scared!"
The initial attack on Mr Iannucci's decision to accept the OBE came when Mr Campbell observed he was joining "the Establishment he claims to deride".
Referring to The Thick Of It's foul-mouthed spin doctor, he added: "Malcolm Tucker and I do not approve of honours system."
Mr Iannucci provoked another response when he tweeted back that it was "more establishment to order your army to march into other countries for no reason".
Mr Campbell responded by claiming the writer's wit was "a bit tired and blunt already". He suggested that "three little letters can have more impact than you realise".
Mr Iannucci simply replied: "WMD."
His latest The Thick Of It series, which he said last night was likely to be the last, features Malcolm Tucker in opposition against a right-wing party and a third party known as 'the inbetweeners'.
Tucker is the show's most memorable character for his blistering tirades against political colleagues and enemies alike.
But Mr Iannucci expressed concern that Mr Campbell views Tucker as a "person to be admired".
"That worries me deeply because for me Malcolm is representative of all this is poisonous and dangerous and that has caused so much disrespect for politics and politicians in the last 15, 20 years," Mr Iannucci added.
"As with all villains - Satan in Paradise Lost, or Darth Vader in Star Wars - we love the Malcolm scenes but we mustn't forget he's a total c***!
"It worries me that he's turned into some kind of hero."