MOSCOW (Reuters) -- British Finance Minister Gordon Brown plans to make national security a priority for his next three-year spending review in order to convince voters they are safe under a Labour government.

In a speech on Monday just days after his party lost the previously safe parliamentary seat of Dunfermline and West Fife, the constituency in which he lives, Brown will say tackling terrorism is the biggest challenge the nation faces.

More than 50 people were killed when a series of bombs hit London's transport network on July 7 2005.

"For nine years as Chancellor, my aim has been a Britain strong in our stability," Brown will say, according to aides. "In the years ahead, I want a Britain both strong in stability and strong in security, so that it can be said not just that our national stability is safe in our hands, but that our national security is safe in our hands."

His comments are likely to reinforce speculation that Brown is increasingly involving himself with all areas of government as he prepares to take over from Prime Minister Tony Blair, who has said he will not fight another election.

Brown will say national security issues dominate decisions in transport, energy, immigration, social security and health. "Coordinating the way we address international terrorism will be a central feature of the coming spending review."

The review, due in 2007, will set out the spending commitments for the three fiscal years starting 2008-09 when many speculate that Brown will be Prime Minister and that the government will be under pressure to restrict spending.

"A priority for the spending review will be to examine our future security needs for intelligence gathering and policing, reviewing the strategic allocation of resources to meet changing requirements," he will say. "For example, detecting explosives in crowded places; looking at the case for a single security budget; and assessing how we secure the best coordination in their delivery and their accountability."

Brown will also set out new measures to cut off terrorist financing and make a case for biometric proof of identity at the heart of the national ID system while ensuring there is proper supervision that police and government powers are not abused.