Number 10 will fill the vacant positions on its Policy Unit today, with three replacements due.
Number 10 has denied claims that Larry the Downing Street cat is disliked by the Cameron family following speculation in a new book.
While Blair and Brown kept their blows behind closed doors, the current residents of No 10 and 11 are seen brazenly brawling in the street.
Chancellor George Osborne's cat Freya has been returned to Downing Street, after being found frightened and lost in Vauxhall, London.
Outreach worker Kate Jones found Freya far from home and identified the wandering feline from a tag on her collar.
Ms Jones said: "I'm not so used to working with homeless cats but when we saw Freya we realised how distressed she was, we did the only right thing possible and helped her get off the streets too."
Freya spent the night on Ms Jones's pillow before being collected by Downing Street officials.
She had somehow travelled south of the river and at least 1.5 miles before being found.
Freya, who moved to Downing Street with the Osborne family in 2010, has reportedly gone missing before, after disappearing from the family's Notting Hill home in 2009.
Irish President Michael D Higgins met Prime Minister David Cameron in Downing Street today as he began day two of his state visit to Britain.
Maria Miller has said she takes "full responsibility" for her decision to resign as Culture Secretary, saying she wants to "make sure that I can move on".
Speaking publicly for the first time since her resignation was announced, Ms Miller said, "I think it is the right thing to do to, remove what has become really an unhelpful and very difficult distraction for colleagues."
Asked if she accepted that she had done something wrong, Ms Miller answered: "I have made it clear and apologised unreservedly to the House of Commons and made sure that it was clear to everybody that I took full responsibility for those findings.
"I want to make sure that the situation is clear to everybody and make sure that I can move on".
Downing Street has insisted David Cameron followed all the "proper processes" after it emerged his family's Nepalese nanny has been granted British citizenship.
Questions were raised about Mr Cameron's use of foreign domestic help after a minister deplored the effects of the "metropolitan elite" using cheap migrant workers.
Home Office minister James Brokenshire said yesterday the wealthy had been the main winners from Britain's openness to labour from abroad, because they had to pay less for tradesmen and services.
Cabinet Secretary Sir Jeremy Heywood has said "there has been no contact from officials" with former No 10 policy adviser Patrick Rock following his arrest over allegations linked to child abuse images.
Responding to Labour's Jon Ashworth who wrote to him demanding further details, Sir Jeremy said he tried "to respond to your specific questions but, as you recognise, in doing so my overriding concern must be to avoid doing anything to prejudice or undermine an on-going police investigation."
He added that the decision not to reveal the claims was made to avoid “jeopardising either [the police’s] investigation or the possibility of a prosecution”.
Labour's shadow cabinet office minister has written to the country's top civil servant asking "a number of important questions" over the arrest of the Prime Minister's former deputy policy adviser over allegations linked to child abuse images.
Following claims of a Downing Street cover-up, Jon Ashworth said there were legitimate concerns "given that Mr [Patrick] Rock had a senior role at the heart of Government."
He asked the Cabinet Secretary Sir Jeremy Heywood for information surrounding Number 10's decision to report Mr Rock to police, including when David Cameron was first made aware of the claims.
David Cameron is facing claims of a Downing Street cover-up after a senior aide was arrested on suspicion of an offence related to child abuse images.
Patrick Rock quietly resigned last month after officials were made aware of a potential offence, but Labour MPs have been asking why it took Number 10 so long to disclose the news.
ITV News Political Correspondent Libby Weiner reports:
Sources close to the Prime Minister have dismissed talk of a cover-up, saying Mr Cameron had spoken out "as soon as he could".
Labour MP John Mann said it was extraordinary that Downing Street did not make any public announcement after the resignation and arrest of former government policy adviser Patrick Rock.
"This is a man in the heart of 10 Downing Street, in the heart of government, couldn't be closer to power, he is part of power, and the fact that they've withheld that information for three weeks is all in all unacceptable," he said.
Explaining why Downing Street didn't make a statement at the time of Mr Rock's resignation, David Cameron said: "I I don't think it would be right to preemptively brief out a criminal investigation and that's why we did not do that."
"But as soon as questions were asked, as questions would inevitably be asked, we have given very full and straightforward answers," the Prime Minister added.
Few will have heard of Patrick Rock before now - except for those in the Tory Party's high command.
At 62, he has had a political career spanning four decades, working with senior party figures such as the former Tory leader Lord Howard, and the former party chairman, Lord Patten.
When the Prime Minister told me today he was "profoundly shocked" to hear of the allegations against Mr Rock involving images of child pornography, that was probably an understatement.
Mr Rock has been a confidant and adviser to David Cameron since the 1990s. The Prime Minister brought him back into the heart of government in 2011 as number two in the policy unit, where Mr Rock worked on issues which included internet filters to protect against child abuse images online.
David Cameron said he had to be careful what he said today because this was an ongoing criminal investigation.
But there was no disguising the fact that - whatever the outcome of the investigation - Mr Rock's arrest and resignation are a serious blow, both personally and professionally.
ITV News Political Correspondent Carl Dinnen has tweeted:
Asked if PM knew of earlier complaint against Rock, PMOS said 'The PM is always kept informed of relevant staffing issues.'