The credibility of the security and intelligence agencies is being hit by ineffective oversight, an influential group of MPs has said.
Scrutinising the work of MI5, MI6 and GCHQ should not be undertaken exclusively by the Intelligence and Security Committee (ISC), the Home Affairs Select Committee said in its latest report on counter-terrorism.
And the MPs have recommended that membership of the nine-strong ISC should be elected like select committees and the ch air should always be a member of the Commons, subject to election by the whole House.
In addition, it said the ISC chair should always be a member of the largest opposition party.
The report comes after the current ISC chair Sir Malcolm Rifkind defended his Committee's role and powers in a speech to Oxford University's Wadham College.
Alluding to John Le Carre's fictional Cold War spy George Smiley, Committee chairman Keith Vaz MP said: "The current system of oversight is designed to scrutinise the work of George Smiley not the 21st century reality of the security and intelligence services.
"The agencies are at the cutting edge of sophistication and are owed an equally refined system of democratic scrutiny.
"It is an embarrassing indictment of our system that some in the media felt compelled to publish leaked information to ensure that matters were heard in Parliament.
"The Intelligence and Security Committee should be given a democratic mandate in the same way as other Select Committees.
"We will then be able to robustly defend our methods of scrutiny and better serve those who protect us, and the public."
The recommendations follow a prolonged period of scrutiny for the intelligence services, triggered by disclosures made by US whistleblower Edward Snowden.
Mr Snowden leaked top-secret documents to a number of locations, including to the Guardian newspaper, revealing details concerning America's National Security Agency (NSA) and UK listening post GCHQ.
In its report, the Committee said as the relevant d epartmental select committee, it ought to be able to take oral evidence from the head of the security service.
A request by the group of MPs for MI5 director general Andrew Parker to appear before them was rejected by the Home Secretary Theresa May.
"Engagement with elected representatives is not, in itself, a danger to national security and to continue to insist so is hyperbole," the report said.
Critics have claimed Mr Snowden's disclosures have aided terrorists, while others believe the move could be illegal.
Earlier this year, Mr Parker warned in a speech that revealing details about the work of GCHQ was a ''gift to terrorists'', while Sir John Sawers, head of MI6, said terrorists were ''rubbing their hands with glee''.
Supporters believe the leaks exposed an abuse of powers among the security and intelligence services in the UK and US and had contributed to a much-needed debate on their oversight and role.
Last night, ISC chair Sir Malcolm attacked the "insidious use of language" by Snowden's supporters.
The Tory MP said labels such as "mass surveillance" and "Orwellian" risked "unforgivably" blurring the distinction between intelligence work in democratic and authoritarian states.
Sir Malcolm highlighted the Committee's strengthened powers, which among other measures allow it to require - as opposed to request - all the information, including raw intelligence, it required.
Emma Carr, acting director of Big Brother Watch, said: "When a senior committee of Parliament says that the current oversight of our intelligence agencies is not fit for purpose, ineffective and undermines the credibility of Parliament, the Government cannot and must not continue to bury its head in the sand.
"This report is a wake-up call to those blindly parroting the line that the UK has the best oversight system in the world.
"The law is out of date, the oversight is weak and the reporting of what happens is patchy at best.
"The public are right to expect better.
"The Deputy Prime Minister, the Shadow Home Secretary and now the Home Affairs Committee all recognise that our surveillance law needs reviewing and oversight needs to be much stronger.
"Those who claim everything is fine are looking increasingly ridiculous.
"The Committee is right to highlight that there is far more information that could be published without jeopardising security.
"Greater transparency will build trust and improve accountability."
Yvette Cooper, Shadow Home Secretary, said: "Our intelligence services do a vital job to keep us safe, and this report confirms the continued terrorist threats they have to work against.
"Much of their work has to remain secret.
"But to maintain public confidence in their important work, there also has to be proper scrutiny and accountability, and the current system of Commissioners isn't effective enough."
Elsewhere in the Home Affairs Select Committee report, the Committee said the Government must do more to dissuade and prevent British citizens from travelling to Syria to fight.
The group of MPs recommended that the Government implement a programme, similar to Channel, the Home Office programme for safeguarding children and adults from being drawn into terrorism, for everyone returning to Britain where there was evidence they had fought in Syria.
It added that the responsibility for counter-terrorism policing should be moved from the Metropolitan Police to the National Crime Agency (NCA).
Mr Vaz added: " Recent events involving Boko Haram, Al-Shabab and al Qaida show the terrorist threat to the UK is as grave as at any point in the past 13 years."
He continued: " Stopping British men and women going to become foreign fighters in Syria and other theatres of conflict, and engaging with them when they return is vital to avoid endangering the security of the UK for many years to come.
"Whether in classrooms, local community centres, or through the global reach of the internet and social media, a clear message needs to be sent to those at risk.
"Fighting in Syria is not the answer and without the Government helping peer-led projects to tackle this problem many more may be lost to radicalisation."
In a statement, the Association of Chief Police Officers (Acpo) and the Terrorism and Allied Matters (TAM) Board - consisting of assistant commissioner Cressida Dick, chief constable Sara Thornton, chief constable Sir Peter Fahy, chief constable Chris Sims, chief constable Mark Gilmore and chief constable Matt Baggott - said they were "concerned" that the Committee had recommended that responsibility for counter-terrorism policing should be moved to the NCA.
The statement described it as "a decision that does not appear to supported by the evidence and is based on an apparent misunderstanding of the role played by the Metropolitan Police Service.
"Counter-terrorism policing is not directed through a single lead force but rather has responsibility vested in nine chief constables across the UK in areas where the threat is considered to be the greatest. These chief constables act collaboratively and effectively on behalf of all forces, while at the same time maintaining close and critical links into local policing."
The statement added: " The Home Secretary has previously confirmed that she will conduct a review of counter-terrorism structures. We welcome any such review and look forward to participating fully and constructively in it. "