The Home Office announced a range of terrorist offences including indirectly inciting terrorism and glorifying terrorist acts but with 90-day detention at the centre of the package.

But a draft letter from Mr Clarke to opposition parties showed that he has doubts about the necessity of the three-month detention period.

It read: “I think the case for some extension is clear though I believe there is room for debate about whether we should go as far as three months and I am still in discussion with police on this point.”

The draft paragraphs were deleted from his final letter, dated yesterday, which said that the Bill supports a proposal by the police for detention before charge to be extended from 14 days to three months.

However, the deletions could be read by checking for previous versions in the electronic version of the letter. A Home Office spokeswoman said: “The Home Secretary has made clear that he’s convinced by the case the police have made to extend the maximum period of detention to three months.

“The changes were made within his office after he had seen the draft.”

Other proposals in the draft Bill include making it an offence for publishers and bookshops to print or sell terrorist publications or material encouraging or inciting terrorism.

It will be a crime to attend terror training camps and a new crime of acts preparatory to terrorism is to be created to help to convict those on the fringes of terror acts. The criteria for banning organisations is to be widened so that the Home Office can meet the Prime Minister’s call for Hizb-ut-Tahrir and al-Mujahiroun to be proscribed. New criteria will include any organisation glorifying or celebrating terrorism.

The plan to create a new offence of glorifying terrorism willl apply to terrorist acts in the past 20 years. It will not be a crime to glorify any events more than 20 years ago except those on a list drawn up by the Home Secretary.

A Home Office spokeswoman said: “Some examples which have been put forward of events which might not qualify for inclusion in the list are the 1916 Easter Uprising in Dublin or the French Revolution.”

The proposed new offence will ignite a debate centred on one person’s freedom fighter being another’s terrorist.

Shami Chakrabarti, director of Liberty, said: “Glorification is so broad that the Home Secretary will take powers to determine which historical figures were terrorists and which freedom fighters.”

The proposal to give police the power to hold a suspect for up to three months was criticised by opposition MPs and civil liberties groups last night.

Chief constables said that they needed the time because of the complexity of investigating international terrorism.

Under Mr Clarke’s proposal police would apply to a district judge, but not a lay magistrate, for weekly extensions of detention up to three months. Mr Clarke is hoping for cross-party consensus for the measures, which will be introduced to Parliament this autum.

MAIN POINTS

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• TV bidding war starts over Olympics
• Sofas were larger than life in TV adverts
• Driver pays fine with wheelbarrow of pennies