A row has broken out between the Conservatives and Liberal Democrats over future voting rights at Westminster.
The Tories accused their former coalition partners of running their general election campaign on “double standards” and claimed they could not be trusted.
The accusation was made after Scottish Lib Dem leader Willie Rennie criticised plans laid out by Prime Minister David Cameron for English votes for English laws (EVEL) following a no vote in the independence referendum last year.
Tory MSP Liz Smith branded Mr Rennie a “hypocrite” because his party stated in a UK Government document that it supported the proposal.
Commenting on the issue, the Lib Dem leader said: “There is no doubt that David Cameron is playing up the division on issues like EVEL.
“The SNP are a threat to our country, they stand on that record, and the Tories are talking them up by proposing their unfair and unreasonable plans on EVEL.
“So both pose a threat to the UK.”
Mr Rennie said the Lib Dems recognised that the constitution of the UK was evolving but reforms must not be timid.
“Most devolution that we have implemented in the UK has been a form of proportional representation, but what the Tories are doing are trying to rig it to just benefit them, so that Tories are in charge rather than the people,” he added.
But Ms Smith said the Lib Dems were guilty of “double standards”.
She pointed out that the Lib Dem section in the government paper states: “It cannot be right that a future government could pursue policies in England in areas devolved to the Scottish Parliament using the votes of Scottish MPs, even if this was not supported in England.
“The so-called West Lothian question can no longer go unanswered.
“The Liberal Democrats believe that English MPs at Westminster should have a stronger voice and a stronger veto over purely English only issues.”
Ms Smith said: “It’s quite astonishing to learn, that once again we find Willie Rennie being hypocritical.
“The Liberal Democrats, as usual, are saying one thing to the people of Scotland and another to others.
“They simply cannot be trusted.
“It’s clear that an SNP deal with Labour poses the greatest threat to our United Kingdom.”