UK EU negotiations: Will 'emergency brake' cut migration?

David Cameron says the draft deal aimed at keeping Britain in the EU will deliver the "substantial change" he has been demanding to how it is run.

The deal, which includes an "emergency brake" on migrant benefits, paves the way for the UK's EU referendum to take place as early as June.

But would this have the effect of reducing the number of EU migrants coming to the UK?

Mark Easton has been investigating.