CLARKE IN WARNING OVER 42-DAY RULE

Despite supporting the Government in last week's knife-edge Commons vote on the issue, he has expressed "very serious doubts" in correspondence with Jacqui Smith.

He told the Home Secretary, ahead of the vote, that concessions she offered Labour rebels to swing them behind the measure rendered the 14-day extension, beyond the current 28-day limit, unusable.

"I remain very concerned about the possibility of ever using this power to extend to 42 days, so that the whole process is worthless from the point of view of national security," he wrote in one of a series of letters obtained by Channel 4 News.

Mr Clarke, who as Tony Blair's home secretary proposed the extension of pre-charge detention for terror suspects to 90 days, predicted "protracted and potentially bitter divisions with the Government" over the issue.

He added: "The new law is likely to turn out to be entirely academic and the whole process will severely damage the fight against terrorism and will only bring discredit on the Government and the Labour Party."

Mr Clarke claimed that his concerns were shared by many of his Labour colleagues who nevertheless supported the Government last week.

Prime Minister Gordon Brown scraped victory in the Commons by just nine votes after picking off a number of potential rebels in the last few weeks.

But it was the nine Democratic Unionist MPs' last-minute decision to support the Bill that proved the decisive factor as 36 Labour MPs revolted. Both the DUP and Mr Brown have denied doing a deal.

The Bill is now headed for the House of Lords where opposition to the 42-day proposal is much greater and it is expected to be thrown out.