Theresa May is gambling that she can draw on the support of disaffected Labour moderates in order to push her beleaguered Brexit plan through the House of Commons.

Allies of the Prime Minister claimed she would ultimately seek the necessary votes to approve a deal through a combination of Labour MPs angered by Jeremy Corbyn's leadership, and "peeling off" ambitious Eurosceptic MPs.

One claimed that the number of Brexiteers who would vote down her deal at all costs could be as low as 15 or 20 - or just a third of the full membership of the European Research Group (ERG) of Eurosceptic backbenchers.

The ally said the votes of disaffected Labour MPs willing to support a "pragmatic" deal could then hand a victory to Mrs May.

A senior minister said the votes of Labour moderates would be "crucial".