Alastair Campbell has written to the Cabinet Secretary to complain that David Cameron "slurred" him during prime minister's questions.
Speaking in the House of Commons on Wednesday, the prime minister dismissed an attempt by a Labour MP to question whether his former communications director Andy Coulson had access to top-secret files he was not supposed to.
"If Andy Coulson was not vetted, why did he attend secret briefings and what documents did he see," Meg Hillier asked. "Isn't this a mess?"
Cameron said his opponents were "desperate to find a smoking gun" but added, "I absolutely tell her this is absolutely not it."
"We took a view on coming to office that in the past too many people had actually been cleared at highest levels, that led to some of the problems in terms of Alistair Campbell," he said.
He added: "When it came to it, Andy Coulson was in the process of being Development Vetted (the highest form of security clearance)."
However following the exchange, Campbell, Tony Blair's former communications director, who himself had DV clearance while working at Number 10, appeared to be unhappy with the implication he had abused his position.
On Twitter he said: "What is Cameron talking about in relation to me and developed vetting? He apologised last time slurred me in Parliament. Hope will do so again.”
He then said: "Have written to Cabinet Secretary asking Cameron to withdraw his comments re DV status today."
Campbell then added: "Last time reply took a week. Hope quicker today."
Both Campbell and Coulson were questioned over their security clearance level during their appearances at the Leveson inquiry.
Coulson, who quit Downing Street because of pressure over his involvement in the phone hacking scandal, told the inquiry that unlike Campbell he only had the lower SC level of clearance.
Questions have been raised about why Coulson was cleared only to SC level in No 10, rather than the tougher DV level.
Lord O'Donnell, who was cabinet secretary at the time, told Leveson he had been keen to keep the numbers of people given the highest vetting to a minimum, to help avoid leaks.
He stressed that SC clearance allowed Coulson to see some secret documents, and it was only after a terrorist incident at East Midlands airport that it was decided he needed to be upgraded. The ex-News of the World editor resigned before the process was complete.
Cameron told Labour MPs today: "There is no mystery about this at all, and I'd go and looks somewhere else."
It is likely they will.