Britain will "have the option" to diverge from European Union rules during a post-Brexit transition period, the minister seen as Theresa May's deputy has said.
In an attempt to reassure discontented Brexiteers, Cabinet Office minister David Lidington said the UK would be free to move away from EU rules after a transition period.
He also claimed that "implementation" period of around two years after Brexit day in March 2019 would still produce "big, big differences" to the current relationship.
Mr Lidington also insisted Chancellor Philip Hammond is "fully on board" with the Government's Brexit strategy amid fresh calls for his sacking from Leavers enraged at his claim UK-EU trade relations would only change "very modestly".
And it came after Donald Trump said he would have taken a "tougher" attitude in Brexit talks than the Prime Minister, in comments which could be seized on by Leavers as evidence she should demand more in negotiations.
Mr Lidington told BBC One's Andrew Marr Show: "Of course we will have the power to choose for ourselves whether or not to diverge once we have left the supranational legal structures of the EU.
"It is then the matter for a British government and a British Parliament to decide, well there may be some areas as the PM set out in Florence where we want to achieve, frankly, the similar objective to the EU27, but to do it in a different way.
"There may be other areas where actually we decide no, actually we have a slightly different objective in this area, (and) others where we're trying to do the same objective through exactly the same means in which case it makes sense for those areas to work very closely together."
Mr Lidington also defended Mr Hammond.
He said: "Philip has made very clear that he's fully on board with the approach that the Prime Minister has set out in both her Lancaster House and Florence speeches last year when she talked about trying to get a deal in the forthcoming negotiations.
"We are leaving, don't be in any doubt about that - but we're having a future trade agreement that we hope will be as frictionless and free trade as we possibly can."
But backbench Brexiteer Nadine Dorries called for Mr Hammond's head, telling ITV's Peston on Sunday: "He has to go, the Chancellor needs to be singing off the Lancaster House hymn sheet along with the Prime Minister, he needs to have the Prime Minister's back and he doesn't.
"There is a tactic amongst the Remain-supporting Conservatives and that is to cause as much chaos as possible and they do that by bowling this curveball every now and then, or a hand grenade right into the middle of proceedings whenever we have a lull.
"The Chancellor has not been loyal, he hasn't got the Prime Minister's back, what we need is stability."
Former cabinet minister Iain Duncan Smith told the Sunday Express: "The Prime Minister cannot govern with Philip Hammond sniping from the sidelines. She has got a serious negotiation on and she does not need the Chancellor contradicting government policy. She needs to say to him: 'You do that again and it will be your last comment as a cabinet minister'."