Sixty eurosceptic Tory MPs from the European Research Group, led by Jacob Rees-Mogg, have sent the Prime Minister a 30 page report detailing their opposition to the plan.
Number 10 have been directly warned in correspondence that accepting a customs partnership will lead to a "collapse" of the government because it would mean Mrs May cannot deliver a clean break from the EU and would lose the support of Brexiteers.
Sources have told the Telegraph that the Tory MPs will consider withdrawing support for Government Bills in Parliament [...]