Theresa May is being criticised over her Brexit objectives by a committee of MPs.
A report published today by the Commons Exiting the European Union Committee suggests the Prime Minister needs to do more to consider the impact of failing to get a deal with the EU, after she claimed "no deal is better than a bad deal."
The report suggests this claim is "unsubstantiated."
However the conclusions have led to division among the Committee, with the report only gaining the backing of 10 out of the 16-strong group, with one Brexit-supporting MP describing the report as "rushed, skewed and partisan".
In the 124-page document entitled "The Government's Negotiating Objectives: The White Paper," MPs observe that the Government has talked about walking away from a bad deal, "but has not yet explained what terms would be demonstrably worse for the UK than 'no deal'."
It advises that the Government should therefore "conduct a thorough assessment of the economic, legal and other implications" of leaving the EU with no deal in place. It suggests that these findings should then be published.
The MPs argue that the public have a right to "the maximum possible information" about the impact of the different future trading options, including the possibility of no free trade agreement being reached.
The report states: "Without an economic assessment of 'no deal' having been done and without evidence that steps are being taken to mitigate what would be the damaging effect of such an outcome the Government's assertion that "no deal is better than a bad deal", is unsubstantiated."
The committee also suggests that, if the Government fails to reach a deal, Parliament should be given a vote over what happens next.
The Government has already been clear that parliament will vote on any future deal, but has not stated what should happen if no agreement is reached.
The report states: "Parliament must be in an informed position to decide whether a proposed deal is, in fact, better or worse than 'no deal'."
However, six members on the committee have refused to agree to the wording of the report. All of them are MPs who supported Brexit.
Committee member Dominic Raab, who was one of those who refused to sign up, told Sky News: "The report was rushed skewed and partisan. After two reports that had strong support, it's regrettable that this one split the committee.
"That undermines its credibility and influence, but I hope and expect the Committee will learn the right lessons, as we move forward."
It comes after a third of the committee left a meeting last week over the drafting of the report - however, Mr Raab denied it had been a "dramatic walk-out".
He said the committee could get back to working properly together as they had on two previous reports.
However, the committee chair Hilary Benn hit back.
He told Sky News the report was "a reasonable, balanced, serious and sober assessment of the Government's negotiating objectives, which we have drawn up after a great deal of evidence and we have to let the evidence speak for itself."
Mr Benn also denied the proposals could lead to Parliament voting to stay in the EU.
He said: "The decision to leave the European Union has been made by British people last summer, this is about the terms in which we leave and the nature of our future relationship."