Ex-Conservative minister Anna Soubry has said a transitional period taking the UK out of the EU could "go on for years", as Tory divisions on Brexit re-emerged.
Ms Soubry said a transition period after 2019 in which Britain could negotiate details of its new status and adjust smoothly to Brexit should be "as long as business needs".
It comes after Chancellor Philip Hammond appeared to challenge Leave-backing colleagues, some of whom favour a fast and hard Brexit, by saying that "thoughtful politicians" should be in favour of a transition.
Ms Soubry told BBC Radio 4’s Today programme: "I’m not saying how long that period should be, it’s as long as business needs."
Responding to whether it could "go on for years" she said that it could.
She said Britain would leave the EU by 2019, but a transitional period would then "smooth that exit fully as we have a new relationship negotiated".
Ms Soubry added: "It makes a great deal of common sense. It’s certainly the view of the businesses that I’ve been speaking to and their trading bodies.
"They see the real benefits of this period where we smoothly get a new arrangement with the EU up and running, giving us the time to negotiate and get that deal, but without jeopardising the economy.
"That’s what a transitional approach would absolutely deliver and I think it’s very good idea."
Former Trade Secretary Peter Lilley, now a Brexit backing Tory backbencher, said a transitional period would be acceptable only if it was to implement changes that had already been decided.
But he added: "If there is any suggestion that we have a temporary agreement lasting a period followed by a permanent agreement, then that can’t be what the Chancellor was saying.
"It would take as long to agree a temporary agreement as it would a permanent agreement so you may as well just go to permanent agreement."
At a select committee on Monday, Mr Hammond called for a "smoother transition" to withdrawal – saying "thoughtful politicians" are now swinging behind an interim trade deal to cushion the harsh impact.
The comments go much further than Theresa May’s public statements, after her spokesman denied she was exploring a transitional deal.
A Lords committee has also said Ms May must secure a "transitional deal" that will see the UK remain a part of the EU’s customs union after 2019.
