UK counter-terror review explained

The two key areas of the government's review of counter-terrorism laws are:

• Detention by police without charge.

• Control orders

Other areas examined included stop and search powers, council snooping powers and whether extreme but non-violent groups could be banned. A lot of the detail will only become clear once legislation is put before Parliament - but the key proposals are laid out in the government's review.

Detention without charge

The old system: Police could hold ordinary criminal suspects for up to four days without charge. Terrorism suspects could be held for up to 28 days - but only six suspects were ever held up to the maximum - and not all of them were charged or convicted.

The new system: The coalition has already allowed 28-day detention to lapse by not putting an annual renewal vote to Parliament. The system has therefore reverted to 14 days detention without charge for terror suspects.

The coalition says in the review it will stick to that position - but it also wants draft legislation available in case it needs to reintroduce 28-day detention in emergency situations, such as if the police are dealing with complex and multiple plots.

The government is also going to produce guidance that will trigger the use of special powers, passed by Parliament in 2008, to question a terror suspects after charge, something that was previously banned.

The issues: Detention without charge was extended for one simple reason: police and security chiefs said plots were getting far more complex and they needed more time to look at evidence, such as decrypting hard drives and then translating material into English.

Another critical factor was the risk of the suicide bomber. If someone is suspected of wanting to blow themselves up, police say they need to act earlier, meaning some of the evidence-gathering would only start once the plot had been contained.

Critics say the power wasn't really needed in the first place. Two of the men held and charged after 21 days in relation to the 2006 airlines bomb plot were never convicted.

Control orders

The old system: Control orders were introduced in 2005 to restrict the freedoms of terrorism suspects whom officials said could neither be charged nor deported.

Suspects are ordered to live at a specific address, which can involve relocation to a town far from their home. They can be subjected to a 16-hour curfew, must wear an electronic tag and report regularly to the police. They can be banned from meeting named individuals and from using mobile phones or the internet.

They are usually confined to a tight area around their home, allowing them to visit a supermarket or shops but keeping them away from train or bus stations.

The home secretary signs an order to control an individual following an MI5 assessment of what the suspect has been up to. That order can be challenged in the courts - but the secret intelligence assessments behind it are not disclosed to the suspect.

The new system: The proposed replacement is called aTerrorism Prevention and Investigation Measures (T-Pim) and ministers say it will allow more liberties while maintaining the ability of the security services to monitor a suspect.

Suspects must live at their home address, but they will not be forcibly relocated. They will be required to stay at home overnight - possibly for up to 10 hours - but officials say this is not a curfew because the restriction would be flexible. A suspect could apply to vary it to stay elsewhere - and the courts would have a greater say over the imposed hours indoors.

T-Pim suspects will be electronically tagged, report regularly to the police and could face "tightly-defined exclusion from particular places and the prevention of travel overseas."

The suspect will be allowed to use a mobile phone and the internet, subject to conditions. They will be allowed "greater freedom of association", including around work and study. T-Pims will expire after two years unless new evidence emerges of involvement in terrorism.

The home secretary would impose a T-pim following an MI5 assessment of what the suspect has been up to. That order would be subject to automatic court challenge and review - but the detailed secret intelligence assessments behind will not be disclosed to the suspect. Beach of a T-Pim could lead to jail - just like now.

The government also wants to devise draft legislation that would reintroduce tougher powers which, on paper, are almost identical to control orders.

The issues: Critics say control orders are manifestly unfair and Kafkaesque. But campaigners who thought that they were on their way out have dubbed the replacement system "control orders lite".

Civil rights group Liberty says the government could have turned to criminal bail. This allows police to arrest and question a suspect - but then bail them with restrictions while they continue to investigate.

Cerie Bullivant, a Muslim convert who successfully challenged his order in 2008, says that control orders act as a recruiting sergeant for extremists - and that the new system won't change that.

In his terror laws review, the former Director of Public Prosecutions Lord Macdonald QC says that control orders place a suspect in a legal limbo and act as an "impediment to prosecution."

The coalition says the new system will make the police work harder at getting prosecutions - and there will be more cash for MI5 surveillance.

Other parts of the review

The government says that controversial counter-terrorism stop and searches remain justified - but only if an officer has reasonable suspicion in a specified area in specific circumstances.

The review also looked at the banning organisations allegedly espousing hatred or violence. The government says it will not extend the definition of terrorism to make it easier to do so because that would interfere with freedom of speech.

The Conservative election manifesto pledged to ban Hizb ut-Tahrir, a radical Islamist organisation, accused of being part of the ideological "conveyor belt" of terrorism. HT, which wants an Islamic state across Muslim countries, denies any links with terrorism. Tony Blair also said he would ban HT - but was told it was not possible because it hadn't done anything wrong.

On surveillance, the government says it will stop councils from using surveillance techniques unless there is a need that can be justified before a magistrate. Some councils have been attacked for using the powers to investigate dog fouling and false claims over school catchment areas.

Labour had already committed to introduce similar reforms in how councils use the Regulation of Investigatory Powers Act (Ripa).