As many as 40 Tory MPs are now backing a bid led by ex-Cabinet ministers Philip Hammond and David Gauke to stop Britain leaving the European Union without a deal on Oct 31.

Sources in the group - dubbed the 'Gauke-ward Squad' - say the numbers of MPs who now support the rebellion has jumped from 21 to nearly 40 after details of the group emerged last week.

The size of the potential rebellion will increase pressure on Boris Johnson to avoid putting the question of the UK leaving the EU to a vote of MPs before the UK is scheduled to leave on October 31.

Mr Johnson and his team are adamant that the best way of securing a new deal with Brussels is to make clear that the UK is ready and willing to leave without a deal.

Last week 21 Tory MPs including former Cabinet ministers Mr Hammond, Mr Gauke, David Lidington, Greg Clark and Rory Stewart broke cover to make clear they are fighting a no deal exit.

In a letter to Mr Johnson they said they were "alarmed" by Mr Johnson's negotiating red lines "which on the face of it appear to eliminate the chance of reaching agreement with the EU".