David Cameron set the stage for a fierce parliamentary battle over terrorism yesterday by signalling that he would resist Gordon Brown’s plans to increase the 28-day limit for holding suspects without charge.

Amid strong indications that the Government is considering doubling the limit, Mr Cameron, speaking on Sunday Live, a Sky News programme, accused Mr Brown of being incoherent for advocating an extension while promising a new chapter in the history of British liberty.

The Tory leader said: “On the one hand to say this is a new chapter of British liberty, but he wants even longer to bang people up without charge or a trial. Totally muddled, totally incoherent. We have always said unless they can produce new evidence about why we should go further than 28 days we don’t see the justification.”

The tough line by Mr Cameron may take some of his MPs by surprise. Some believe that the party should be ready to move on the 28-day limit to avoid Mr Brown being able to make political capital out of the Counter-Terrorism Bill. There are some Conservative concerns because Lord Carlile of Berriew, the Government’s terror law watchdog, has backed an extension in a limited number of cases. The Liberal Democrat peer told the The Politics Show on BBC One yesterday: “I think there is a small number of cases, possibly a very small number but of very important cases, for which a 28-day period may be insufficient.” The recent case of Kafeel Ahmed, who died of his injuries more than 28 days after the alleged attempted terrorist attack at Glasgow airport, showed why an extension may be needed, he added. He also said that terrorists used computer systems that could take a long time to crack.

Lord Carlile said that there was no logical answer to the maximum amount of days a suspect should be held and proposed involving a senior judge at an early stage to determine whether detention was justified.

Shahid Malik, the Minister for International Development, had his baggage tested for explosives at an American airport on his way home from talks on tackling terrorism. Mr Malik, who is Muslim, was searched and detained for 40 minutes by the Department of Homeland Security at Dulles airport in Washington DC. Mr Malik said that the US system did not “inspire confidence”. He said that two other Muslim men with him had also been detained.

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