Do SNP MSPs truly believe it is acceptable to manipulate the business of Scottish parliament committees just to make life easier for ministers?

There has been disquiet for years about the way in which the SNP have used their majority at Holyrood to stop committees acting in any way that might prove embarrassing for ministers but, if anything, the tendency may be worsening as the independence referendum approaches.

The primary role of Scottish parliament committees is to hold the Scottish Government to account. That role is not just something to occupy MSPs between constituency surgeries and First Minister's Questions; it is absolutely essential to the proper functioning of democracy in Scotland. With a unicameral parliament, committees perform a vital function in testing legislation and interrogating government policies. MSPs sitting on committees are supposed to put their political leanings to one side but there have been mounting claims that this duty is less important to many SNP MSPs than sparing their political masters any discomfort.

Accusations have been made that SNP members of the Public Petitions Committee have sought to prevent any discussion of constitutional referendums for oil-rich Shetland, Orkney and the Western Isles because it could prove awkward for Alex Salmond. Quite apart from the farcical notion of MSPs who support Scottish independence seeking to suppress discussion of independence for Scotland's island groups, any SNP member acting in this way would be failing to live up to their responsibilities as committee members. Equally worrying is the suggestion that constitutional expert Matt Qvortrup was called before the finance committee by SNP members only to be disinvited after submitting written evidence that did not quite stay on message from the SNP's perspective (Mr Qvortrup noted that there was no guarantee of EU or UN entry for an independent Scotland).

Last week, Tory, Labour and Liberal Democrat members of Holyrood's Public Audit Committee refused to endorse the committee's official report on the setting up of Police Scotland, voted through by the SNP's committee majority, because their criticisms of the Government had been removed from it. Holding a joint press conference on Tuesday, they said a "cult of slavishness and obedience" had been imposed on SNP backbenchers. The Scottish Government's "failures and inconsistencies" were being suppressed, they argued.

While Labour were known for imposing strong discipline in the ranks while in coalition with the Liberal Democrats, there was not the same level of disquiet about committees properly fulfilling their duties during their tenure in office.

The SNP party leadership and MSPs must take responsibility for this. To dismiss accusations about controlling behaviour as posturing by their political opponents is simply not good enough. Such behaviour does not support the proper functioning of the parliamentary process and has no place in it.