The SNP's hopes of using the same question in a future independence referendum from the 2014 vote have been dealt a blow in a report published by Holyrood's constitution committee today.
It has called for the elections watchdog, the Electoral Commission, to be have a role in testing the question to be used - which could see the body rule out a Yes/No question.
The testing process would also take months which could delay the timetable for a vote - although it could still happen next year in line with Nicola Sturgeon's plans.
Scots were asked a "Yes/No" question in 2014 - "Should Scotland be an Independent Country?" - which was tested by the Electoral Commission.
The Referendums (Scotland) Bill says that where the Commission has already tested a question, there is no need to do so again. The watchdog has objected to the prospect of being frozen out.
Today's report says the Scottish Government's Constitution Secretary Mike Russell should recognise the "the weight of evidence in favour of the Electoral Commission testing a previously used referendum question and must come to an agreement based on this evidence with the Electoral Commission prior to Stage 2."
Since 2014, the Commission has ruled out a Yes/No question in the Brexit referendum, after research found it could result in bias in favour of the "positive" Yes response. Instead voters were asked if they wish to "Remain or Leave" on the EU issue.
The Committee backs the general policy objectives of the Bill.
Convener Bruce Crawford said: “We welcome the approach taken by the Cabinet Secretary in his oral evidence to our committee where he indicated that he is “open to alternative approaches to all aspects of the Bill” and how it can be improved.
“Our recommendations are intentionally framed to inform an open discussion on how the Bill can be improved based on the substantial evidence received.”
Mr Russell said he would "seriously consider" the report’s findings.
But he added: “There is still a strong case, in my view, for not changing a question which has been previously proposed and tested by the Electoral Commission, remains in use and has the confidence of the public. However, I am open to constructive proposals.”
But Pamela Nash, chief executive of Scotland in Union, welcomed the report's findings.
"It’s a crushing blow for the SNP in its disgraceful attempts to rig any future referendum on leaving the UK," she said.
“This Bill should never have been introduced in the first place, as it has taken up parliamentary time when barely a quarter of people in Scotland support a divisive second independence referendum within the SNP’s timeframe.
“But the SNP’s attempts to bypass the independent Electoral Commission were shameful."