Tonight’s Panorama programme will reveal that the number of illegal immigrants in London and the UK are well above previous estimates. The latest estimate is that in 2007 there were between 524,000 to 947,000 illegal immigrants in the UK (central estimate 725,000). Previous estimates of illegal immigrants in the UK in 2001 were 310,000 – 570,000 (central estimate 430,000).  Boris Johnson will tell the programme that, in the absence of a credible deportation regime, he is open to the regularisation of these illegal immigrants so that they pay taxes (not something they currently do) in order to pay for their use of public services (something they do currently do).

ConservativeHome has been provided this verbatim preview of an exchange between Mayor Boris Johnson and the Panorama interviewer:

"Panorama – ‘Why do you support the idea of an earned amnesty?’

Mayor – ‘We are not at that stage yet. What we have is a report by the LSE, that shows there are 500,000 people who are irregular migrants in London, from people breaking the law all sorts of people who are waiting for their papers to come through and there is a huge issue in dealing with that, because we are not sending them back because of the failure of Government policies, irregular migrants are not being sent back, only a maximum of 12,000 a year.’

Panorama – ‘Why?’

Mayor – ‘Failure of the Government. If you go on on this rate it will take 60 years to clear the backlog.’

Panorama – ‘60 years?’

Mayor – ‘It’s extremely expensive to deport migrants, let me be clear I am in favour of sending them back but we must be realistic. We need to do two things simultaneously if we are serious, first we need to tighten the borders, we need to be much more robust because we don’t know who is here, it’s crazy. Secondly we need a frank debate about what to do with the half a million who are not able to join the economy legally but are not allowed to make contribution to society and make case for earned amnesty, if they have been here for a long time and it looks like and if they can make a contribution they should be given the chance to regualrise their status.’"