The SNP has been accused of "doctoring" a Holyrood committee report on Scotland's place in Europe to reflect more pro-independence views.
The claim comes days after opposition members said the party of government is abusing its majority to stifle criticism.
The fresh row centres on the findings of the European and External Affairs Committee.
Labour and Tory members complain they were blocked from publishing the original draft and a "minority view" as part of the final report.
The SNP used its majority to add an entire section on concerns about a possible UK exit from the European Union (EU).
Much of the short conclusion - which promotes the role of small states in the EU - was signed off thanks to SNP votes.
However, the report also reflects the view that Scotland may have to reapply for membership of the EU after a vote for independence on September 18.
The SNP said their opponents are "playing politics" and undermining the Scottish Parliament committee system.
But Scottish Conservative MSP Jamie McGrigor, who sits on the committee, said: "The original draft report produced by the clerks was a clear, impartial reflection of the evidence the committee had received.
"However, it soon became clear the SNP members wanted to doctor this and include more pro-independence arguments, instead of a true record of what was heard.
"We are completely unsatisfied with the report and its conclusions, which differ greatly from the original draft. The SNP has used its in-built majority to gag opposing views, and that is a disgrace."
Labour MSP Alex Rowley, who also sits on the committee, said: " It's hugely frustrating that after taking evidence to give a balanced picture of Scotland's relationship with Europe that the SNP has used its majority position to produce a report which doesn't accurately reflect the overall picture.
"This is the third time in less than a month that we've seen the SNP actively suppress views brought forward at committees simply because the conclusions drawn do not align with their own agenda."
Last week, Labour MSP Hugh Henry - backed by Tory and Lib Dem members - said the SNP has adopted a cult of slavishness to the party's leadership rather than trying to hold the government to account.
Mr Henry spoke out when his Public Audit Committee published a report on police reform on May 13.
Two versions of that report were published together - one endorsed by the SNP majority and another with additional criticism of the move to a new national police force.
On the European committee, Mr McGrigor and the two Labour members were prevented from adding their minority view.
Committee convener Christine McKelvie proposed a section on a UK referendum on EU membership, supported by her SNP colleagues, during a private session of the committee.
Repeated references are made to the Scottish Government's case for seamless re-entry to the EU as a member state.
That route, known as Article 48, is questioned by critics and officials including Viviane Reding, vice-president of the European Commission. She says new entrants must apply through Article 49, which could take longer to agree.
SNP votes also ensured the report states that no representative of an EU institution has commented specifically on Scottish independence.
Opposition members failed to stop criticism being noted of a reference to Scotland being compared with Kosovo, including claims that EC president Jose Manuel Barroso had tried to make a "political point".
SNP MSP Willie Coffey said: "The attacks levelled at Scottish Parliament committees are simply not supported by the facts and the opposition parties should stop trying to undermine Holyrood's committee system.
"SNP MSPs on committees take their roles very seriously and it must be recognised that the cross-party nature of committee work means that there are sometimes areas on which agreement can't be reached. In these cases, votes are taken and a democratic decision is reached.
"In office in Scotland, Labour argued that the then Scottish Executive parties had a majority on committees because of the public vote. It seems this point has been conveniently forgotten now they are in opposition.
"The opposition parties need to stop playing the politics of opposition for opposition's sake and get back to the job of representing the people of Scotland."
External Affairs Secretary Fiona Hyslop said: " Quite simply it is in the best interests of those throughout the EU for Scotland and its citizens to remain part of the EU - and this report shows a number of leading experts support that position."