Britain needs a U.S.-style national security adviser to report to Prime Minister Gordon Brown on terrorist threats, a committee of lawmakers said Tuesday in a report that made unusually sharp criticisms of the country's approach to security.

Parliament's Home Affairs select committee said Britain's government had been too slow to adapt to an evolving threat from terrorism and complained that key strategic decisions are often made in informal meetings, rather than by a publicly accountable security panel.

The committee, led by governing Labour Party lawmaker Keith Vaz — a former minister, urged Brown to overturn a ban on the use of intercepted evidence and called for a house arrest-type regime used against some terrorism suspects to be abandoned.

It criticized how Britain's counterterrorism apparatus is structured, saying a confusing number of government committees and departments are responsible for making decisions — often with little public oversight. The committee has the "impression that a degree of institutional inertia has set in," inside the government, the report said.

"We are not confident that government institutions have the desire to constantly adapt to meet ever-changing threats," the committee said.

In 2005, Britain experienced a major terrorism attack in London when four suicide bombers killed 52 commuters on three subway trains and a bus; an almost identical attack two weeks later failed. In June 2007, terrorists left two explosives-laden cars in the heart of London's entertainment district but they failed to detonate, and the same group crashed a blazing sport utility vehicle into Glasgow Airport.

In its report, Vaz's committee said "prominent, publicly accountable national security advisers must be appointed," to provide Brown with expert advice and be available to explain threats to legislators.

In 2007, Brown appointed Alan West, a former head of military intelligence, as a House of Lords member and his government's security minister. However, Vaz's panel said that experts who are not legislators, like President Barack Obama's security adviser Gen. Jim Jones, should also be appointed.

The panel complained key security strategy was being set at an informal weekly meeting of ministers, intelligence service officials and police — and called for a formal national security committee to be established.

In its report, the committee said it had until recently been unaware of the weekly security meeting. "The lack of public awareness of its existence is troubling," the lawmakers said. "The public have a right to know who is protecting them from terrorist threats and in turn, those protecting the public should expect to be accountable."

Britain's system of control orders, a system of curfews used to curtail the movements of terror suspects who can't be brought to trial without revealing sensitive intelligence, is no longer appropriate, the committee said. "It is fundamentally wrong to deprive individuals of their liberty without revealing why," the panel's report added.

The committee recommended that intercept evidence should be permitted in British courts, which would allow more of those held under control orders to be prosecuted.

Britain is one of the few countries in the world to bar the use of evidence from intercepted personal phone calls, e-mails, letters and faxes. Intelligence agencies have resisted attempts to allow such evidence, fearing it would expose their surveillance techniques to public scrutiny.

Home Secretary Alan Johnson said the committee's criticisms were "unsubstantiated and wholly inaccurate," insisting Britain's government had the correct approach to security risks.