The SNP has been accused of misusing parliamentary funds to promote their candidates in the council elections.
Rob Gibson MSP has used parliamentary allowances to place adverts in local newspapers across his area which featured the MSP and, unusually, gave equal billing to his staff members.
Mr Gibson’s staff members are also SNP candidates in the local government elections.
This follows last week's reports that their national election convener misused his position as local government minister to give advantage to the SNP in the council elections. Despite strict rules, Derek Mackay announced £40million for councils two weeks out from polling day.
Lib Dem MSP Tavish Scott has written to the Presiding Officer and the Highland Council Returning Officer to seek an investigation.
Commenting, Mr Scott said:
"The SNP seem to think they have the right to bend, twist and break all the rules now that they have a majority in the parliament. Using public funds to buy votes is something you would expect from corrupt dictators rather than in a modern, democratic Scotland.
"The SNP have been caught red-handed misusing public funds to rig the election. In using his position as an MSP to promote his staff while they are SNP candidates, Mr Gibson has made it a hatrick of SNP election scandals.
“In the last week, Ministers have broken election rules by announcing extra money for councils during an election period, revealed their double standards by delaying politically sensitive decisions over the new northern isles ferry and now promoted candidates using public funds.
“The election expense returns of SNP candidates across Scotland will make for interesting reading.
“Strict rules exist to ensure the governing party cannot use public office for party political gain, but appointing Derek Mackay as their election coordinator while he is local government minister shows just how far they are willing to go to rig results.
“Mr Mackay must be suspended from his post and an immediate investigation launched into the SNP misuse of public funds.”