Rules barring illegal migrants from winning British citizenship are facing a potentially explosive legal challenge on human rights grounds.

The application for a judicial review could leave the Government unable to block applications from migrants, the Daily Mail can reveal.

It comes as the Home Office confirmed only 26 migrants have been removed under Labour’s ‘one in, one out’ deal with France, while more than 10,000 have reached Britain since the scheme’s launch.

It includes 1,075 on Wednesday alone – the third highest daily number so far this year.

Labour introduced new measures in February which say anyone making an application for UK nationality will ‘normally be refused’ if they previously entered the country illegally, such as by small boat.