OTTAWA--The NDP wants the Conservative government to admit it made a mistake in appointing Arthur Porter as the head of Canada's spy watchdog.

The New Democrats are seizing on the news that the government introduced strict new security vetting for nominees to the committee after Porter resigned in 2011 amid concerns about his business dealings.

Appointees to the Security Intelligence Review Committee now must be security cleared to the top-secret level -- a rigorous process that wasn't in place when Porter joined in 2008 or became chairman in 2010.

During question period today, Alexandre Boulerice, the NDP's deputy ethics critic, is urging the government to acknowledge it should not have given Porter such a key position.

Public Safety Minister Vic Toews says the NDP and Liberals were consulted ahead of Porter's appointment -- as is custom with review committee nominees -- and had no objections.

The Prime Minister's Office tightened the security screening requirements following Porter's abrupt departure in November 2011.