London ? Police have questioned Prime Minister Tony Blair for a second time about allegations that political honors – including seats in Britain’s House of Lords – were traded for cash, his official spokesman said Thursday.

The revelation prompted opposition calls for Blair to step down sooner than planned.

Blair was interviewed Jan. 26 as a witness, Blair’s office said. Police confirmed they requested details be kept secret for “operational reasons,” but did not elaborate.

The prime minister was “interviewed briefly to clarify points emerging from the ongoing investigation,” London’s Metropolitan Police said in a statement. “He was interviewed as a witness, not as a suspect, and cooperated fully.”

Police are investigating allegations that honors, including seats in the House of Lords and knighthoods, were given to individuals who loaned money to Blair’s Labour Party or the main opposition Conservatives.

The British leader, who was not accompanied by a lawyer, was questioned for less than an hour at his office before he left London to travel to the World Economic Forum in Switzerland.

“At the request of the police, this was kept utterly confidential,” the prime minister’s spokesman told reporters at a daily briefing. He speaks to the media only on condition of anonymity.

Blair was told in advance that police wished to impose a news blackout on the interview but was not informed of the reasons why, his spokesman said.

“One assumes the police are fully aware of the implications of what they were asking,” he said.

Blair’s chief fundraiser, Lord Levy, was arrested for a second time Tuesday by police investigating the claims and later released on bail.

Three others arrested are Ruth Turner, Blair’s director of government relations; Sir Christopher Evans, a biotechnology entrepreneur, and Des Smith, a government adviser.