The Express front page today claimed there was "fury over Britain's 2m illegal migrants".
The article says the figures "emerged last night" and come from research by Migration Watch UK. But the think tank has denied this, tweeting that the figure is not based on its research "but a very old estimate of illegal immigrants in UK that is no longer applicable".
As we've covered before, Migration Watch's 2010 estimate was that there were 1.1 million illegal migrants living in the UK. It estimated that if they were given citizenship, that would mean giving citizenship to 2 million people in total once their dependants were factored in. So the 2 million figure wasn't an estimate of the number of illegal immigrants in the UK.
The fact is, we don't know how many immigrants are in the UK illegally as they're hidden from the authorities. Other research - this time related to 2007 - has estimated the figure as anywhere between 417,000 and 863,000. We're not aware of more recently published estimates.