LONDON (AFP) — Prime Minister Gordon Brown has announced an independent inquiry into the Iraq war but is facing claims of a cover-up after saying it would take evidence in private.

Six years after predecessor Tony Blair controversially backed the US-led invasion, Brown said the "unprecedented" inquiry would cover the eight years from the campaign's run-up to the pullout of British troops next month.

But he said it would be held in private for "national security" reasons, infuriating many MPs and anti-war campaigners.

Brown is currently bidding to reassert his authority over his ruling Labour Party after his leadership took a hit from an expenses scandal, historically bad European and local election results and a wave of ministerial resignations.

An inquiry has long been sought by many Labour MPs, although the nature of the investigation announced on Monday sparked anger.