David Cameron has raised the political stakes over the controversial arrest of one of his senior Tory MPs - demanding Gordon Brown denounce the move or face charges of hypocrisy. The Prime Minister declared that the decision to question Damian Green and search his home and offices was "a matter for the police" of which he had no prior knowledge. But amid mounting anger and disquiet at Westminster over the action, taken in relation to alleged leaks of sensitive Home Office material, Mr Cameron said the PM had a duty to speak out. Mr Cameron insisted the arrest was "not about our national security but government embarrassment" and added: "When it comes to vigorous opposition, if this approach had been in place in the 1990s, then Gordon Brown would have spent most of his time under arrest. "He made his career from passing on Whitehall leaks. And he'll be guilty of hypocrisy if he doesn't speak out. "The question is: does he think it is right for an MP who has apparently done nothing to breach our national security - and everything to inform the public of information they're entitled to know - to have his home and office searched by a dozen counter-terrorist police officers, his phone, Blackberry and computers confiscated, and to be arrested and held for nine hours?" Mr Cameron also turned his fire on the Commons authorities for apparently "not thinking twice" about allowing officers to raid his immigration spokesman's office in Parliament. Speaker Michael Martin has faced calls for his resignation over the matter. Mr Martin's office has said only that "there is a process to be followed and that was followed" but the Home Office confirmed permission would have been required from the House authorities. Scotland Yard said that Mr Green was held "on suspicion of conspiring to commit misconduct in a public office and aiding and abetting, counselling or procuring misconduct in a public office". He has expressed astonishment at being detained, insisting that he had been doing his public duty in holding the Government to account and would continue to do so. The leaks are thought have included the disclosure that 5,000 illegal immigrants were working as security guards and bouncers; news that an illegal immigrant was employed as a cleaner in the House of Commons; a whip's list of potential Labour rebels against 42-day detention for terror suspects; and a letter from Home Secretary Jacqui Smith to Mr Brown warning that the recession would spark a rise in crime. The police actions have united all sides at Westminster in condemnation, with Liberal Democrat leader Nick Clegg dubbing it "something you might expect from a tin-pot dictatorship" and veteran Labour former Cabinet minister Tony Benn complaining of a "direct attack on Parliamentary democracy by the police". Mr Cameron wrote: "Of course no one is above the law. But in a democracy there is an important line to be drawn when it comes to acting in the public interest."