Reality Check: Do EU migrants take jobs from UK-born workers?
The claim: The number of migrant workers coming to the UK makes it more difficult for UK-born workers to find jobs - for every 100 migrants who get a job, 23 UK-born workers are displaced.
Reality Check verdict: This figure does not show the impact of EU migrants. It refers to non-EU migrants and there are further important caveats - those who stay for more than five years do not displace British-born workers, the impact is significant in times of economic downturn only, and it is not considered permanent.
Iain Duncan Smith has been talking about the effect of migration on workers in the construction industry.
He said: "The government's own Migration Advisory Committee reported that for every 100 migrants employed 23 UK-born workers would have been displaced."
The figure does appear in a 2012 report by the government's independent committee.
But what Mr Duncan Smith doesn't mention is that the figure referred to is the impact of migrants from outside the EU coming to the UK between 1995 and 2010.
No statistically significant effects were found for EU migrants coming to the UK.
There are also a few important caveats to the findings.
Firstly, those migrants who had been in the UK for five years or more were not found to displace British-born workers.
Secondly, the impact of migration on native employment was only significant in times of economic downturn, not in buoyant economic times.
Thirdly, the displacement found should not be considered permanent.