LONDON - Britain's deputy prime minister called for urgent checks to see if the arrest last weekend of a journalist's partner under anti-terrorism laws was legal, distancing himself from his coalition partners who defended the nine-hour detention.
Nick Clegg said on Saturday he was not consulted before the detention of David Miranda, the partner of American journalist Glenn Greenwald, who led coverage of former National Security Agency contractor Edward Snowden's leaks about US and British electronic spying.
The contrasting responses to Miranda's arrest from Britain's governing coalition partners come as battle lines are being drawn for a general election in 2015.
Clegg's Liberal Democrats have held fast to Prime Minister David Cameron's Conservatives in vital areas such as economic policy but they disagree over issues ranging from Britain's role in Europe and its nuclear deterrent.
Miranda, a Brazilian, was carrying documents held on computer between Greenwald and one of Snowden's contacts when British police detained him last Sunday, triggering a complaint from Brazil's government and criticism from British opposition politicians, rights lawyers and the press freedom watchdog.
Miranda was later released without charge minus his laptop, telephone, a computer hard drive and memory sticks.
On Thursday, the police said the documents were "highly sensitive" and, if disclosed, could put lives at risk.
Home Secretary Theresa May, a Conservative, defended the police's use of anti-terrorism powers on Tuesday, saying they were entitled to take security measures if they thought the data he was carrying put lives at risk.
Writing in the Guardian newspaper, which published many of Snowden's leaks, Clegg said he was not consulted before Miranda was detained under Schedule 7 of Britain's Terrorism Act, which allows police to stop and question passengers travelling through airports and ports to determine whether they are involved in planning terrorist acts.
"I acknowledge the many concerns raised about the use of Schedule 7 of the Terrorism Act 2000 for these purposes," he wrote.
"It is immensely important that the independent reviewer of terrorism powers, David Anderson QC, reports rapidly on whether this was a legitimate use of the Terrorism Act, and whether that legislation should be adjusted."
David Anderson, a lawyer who acts as Britain's Independent Reviewer of Terrorism Legislation, wrote to Home Secretary May on Thursday to say he would investigate whether the powers under which police detained Miranda were used lawfully.
Clegg, whose party has traditionally campaigned for civil liberties and open government, said there were already plans to limit the powers of Schedule 7, such as reducing the maximum period of detention to six hours.
He said he would be taking a bill through parliament to implement those changes.