Two British government departments have refused to publish legal advice given to Prime Minister David Cameron before he authorized lethal drone strikes against Islamic State targets in Syria.

Freedom of Information (FoI) requests submitted by the Press Association were rebuffed by the Attorney General’s Office and the Cabinet Office, who both cited the importance of keeping secret legal advice obtained by senior government figures.

The PM has said the targeted killing of two British Islamic State militants in August was “entirely lawful” under international law and that Attorney General Jeremy Wright was consulted beforehand.

Critics of the policy contend the drone strikes amount to extrajudicial killings and as such are a violation of international law.

Cameron authorized the targeted killing of British jihadists in an RAF drone strike in August.

The militants fighting for Islamic State (formerly known as ISIS/ISIL) killed in the attack are believed to be Ruhul Amin, 26, from Aberdeen, and Reyaad Khan, 21, from Cardiff. No civilians were reported to have been killed in the airstrike.

In near identical replies, the Attorney General’s Office and the Cabinet Office confirmed they hold information “falling within the scope of your request.”

However, they refused to provide the material, citing six exemptions under the Freedom of Information Act.

They were: “Information supplied by, or relating to, bodies dealing with security matters; defence; international relations; information relating to the provision of advice by any of the law officers or any request for the provision of such advice; protection of personal data; and legal professional privilege.”

According to the Press Association, the exemptions on security and personal data are “absolute,” while the others are “qualified,” meaning government officials must determine whether it is in the public interest to make them disclose the information.

“[We] recognise that there is a public interest in demonstrating to the public that the government sought and received appropriate professional legal advice, and that this military action took place in accordance with the rule of law,” the Attorney’s General Office and the Cabinet Office said in their replies.

However, “the public interest in maintaining legal professional privilege, and in particular in maintaining the confidentiality of legal advice provided by the law officers, is of particular importance in this case,” the statements said.

“There is a strong public interest in the prime minister, secretary of state for defence and government more broadly being able to seek legal advice in confidence.”

"The particular importance of maintaining the confidentiality of advice given by the law officers is reflected in the convention, observed by successive governments, that their advice should not be disclosed outside government,” the letters said.

The departments added that this public interest is heightened in the context of intelligence, defense, national security and foreign relations.

Richard Arkless, a Scottish National Party MP, asked the Attorney General last month if the legal advice concerning drone strikes would be given on a case-by-case basis, or whether had he given the government “blanket authority” to authorize killings.

Wright refused to answer the question at the time, saying: “I can’t I’m afraid go into the detail of the advice that I gave.”

Upon announcing the drone strikes last month, Cameron justified the killings as an act of self-defense under Article 51 of the United Nations Charter.

Last month, Reprieve legal director Kat Craig criticized the Attorney General’s reluctance to discuss the legal advice he gave the PM.

“It is alarming that the Attorney General does not feel the need to tell MPs or the public even the most broad details about the UK’s kill policy,” Craig said.

“All we currently know is that the prime minister thinks he can authorize the killing of anyone, anywhere, without any parliamentary or judicial oversight.

“The UK appears to be going down the US route of a counterproductive, secret drone war which does more harm than good.”

She added: “When even US generals are warning that the drone program causes more problems than it solves, it beggars belief that the British government is adopting the model in full. We need a real debate, and for that we need the government to come clean about this policy.”