Conservative MP Alun Cairns told ITV News that a report on official migration statistics shows there is a significant margin for error in the way the data is collected.
He said: "We need to be confident the data is absolutely robust. The Government can be assessed on the trends, they can claim some sort of success, but to be confident about the absolute numbers on which this public policy is based we need to have more robust data."
Cairns suggested these measures:
- Home Office to collect more data and ensure data on Visas etc. is compatible
- Use e-Border controls more efficiently to ensure that that data is fed in
- Compare e-Border data with Office of National Statistics
- Compare e-Border data with information from overseas nations