The proposed question for the independence referendum is "biased" towards a yes vote, MPs have argued.
The House of Commons Scottish Affairs Committee concluded that the question "Do you agree that Scotland should be an independent country?" is "leading" and "biased towards a Yes answer".
In a report released on Tuesday entitled "Do you agree that this is a biased question?", the committee has called on all parties to come together immediately to draft a "clear and neutral" question, which can then be put through "exhaustive" testing by the Electoral Commission.
The report stated: "Based on the evidence, we have no choice but to conclude that the question is biased.
"Experts told us that this was a leading question, biased towards a Yes answer. This is important because wording can affect the result of a referendum."
The report goes on to say that a referendum must be, and be seen to be, "fair and acceptable to those on both sides of the argument."
It adds: "It is now widely agreed that the Electoral Commission is the appropriate body to regulate a referendum and ensure that the wording of the question is clear and fair. This means an exhaustive process of testing of proposed words and how the options are put to the voters.
"This will take some time, and therefore it must be started soon. It need not wait until a referendum Bill is drafted. Debate needs to move on to the policies and issues of separation.
"Accordingly, we recommend that all parties approach the Electoral Commission now, so that proposed question wordings can be tested.
"The best course is for the parties to agree jointly what question wordings should be put to the Commission. If a consensus cannot be reached, those parties who can agree should approach the Commission together.
"Our objective is that all can accept the advice of the Commission on a clear and neutral question, which can be incorporated into the legislative process from the very beginning."
The SNP administration put its proposed question out to public consultation in January, with the deadline for responses approaching this Friday.
Scottish Conservative deputy leader Jackson Carlaw said: "This interim report adds compelling testimony to support what most Scots instinctively knew - that Alex Salmond's proposed referendum question was unfair and biased.
"This decision is too important for the final question to be set at the whim of any one politician - it must be simple, fair and judged to be both by the Electoral Commission."
Scottish Government Cabinet Secretary for Parliamentary Business Bruce Crawford said: "Given that this committee can't even get the name of the Scottish Government's policy right, this exercise is devoid of credibility.
"The real issue is that Scotland needs job-creating powers to grow the economy and boost employment.
"The Scottish Government's proposed referendum question is straightforward and fair - as acknowledged by Scottish Tory leader Ruth Davidson - and the 'agree' formulation was also used in Labour's 1997 devolution referendum, and is the same wording used by the Tory/Lib Dem coalition for local referendums in England.
"As set out in the consultation document, the ballot paper will be subject to testing during autumn and winter this year, and we will be delighted to receive advice from the Electoral Commission and other electoral professionals."