Why businesses shouldn't be given exclusive control of utilities: because they have no incentive to maintain them.
"Bob Crow, head of the Rail Maritime and Transport Union (RMT), threatened to recommend a ballot of members unless contracts given to private companies this year were suspended.
He said: "Track walks to check the tracks used to be done every day - now they are only done once a week."
There have been three tube derailments in the last few months - but only on the lines whose maintenance has been privatized.