Londoners will be able to vote in American presidential-style primaries to choose Labour's next candidate for mayor.
Party members and people who register as Labour supporters can have their say.
The change announced today by Ed Miliband reduces the impact of trade unions on the selection of candidates.
The details now from our Political Correspondent Simon Harris
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Rahman was ejected from his powerful job in April by an Election Commissioner after being accused of corrupt and illegal practices.
The service was due to start in September but there is no agreement on pay and conditions such as how many night shifts staff will work.
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