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London mayor election: Portillo not voting for Johnson

20 April 2012 Last updated at 11:33 BST

A former Conservative Defence Secretary has failed to give any backing to the Tory candidate in the London mayoral election.

Michael Portillo said he wanted a mayor who supported a third runway at Heathrow Airport.

He did not name who would get his vote, although only the independent Siobhan Benita is backing such a policy.

Mr Portillo has previously been teased on This Week about his lack of support for Boris Johnson.

BBC Vote 2012

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