The Scottish Liberal Democrat leader Willie Rennie has expressed his concerns over the growth in support for independence.
Rennie said the Scottish Conservative leader Ruth Davidson should be "embarassed" over rising support for independence since her party became the second largest group in Holyrood after May's election.
His concerns were expressed at the last session of First Minister's Questions before Holyrood moves into summer recess.
The Lib Dem leader said: "I don't know if she [the First Minister] felt the same but I found it difficult to belive that Ruth Davidson showed no signs of embarrassmentat all when she claimed to stand up for our place in the United Kingdom a few minutes ago.
"Within weeks of becoming leader of the - apparently offical - opposition support for independence is now at a record high. God help the Union if it carries on like that".
Rennie however went on to reiterate he continues to "oppose independence" but will support the First Minister in "her efforts to maintain a strong relationship with the European Union".
Several opinion polls have indicated in recent days that support for independence has grown since the EU referendum result.
The Lib Dem leader's comments come some days after members of his party voiced their support for a second independence referendum to him and his fellow Liberal Democrat MSPs at a meeting in Edinburgh.
Membership of the European project has been a fundemantal strand of British liberalism since the mid 20th century.
The Scottish Conservative leader used her final questions before the summer recess to underline how she believes the Scottish economy benefits from being part of the United Kingdom.
Davidson said the European Union's single market "is not as important" as being part of the UK's.
She said: "Our exports to the EU are worth £11.6bn but our exports to the UK are worth £48.5bn.
"The UK single market is four times more imporant to our firms here in Scotland and is underpinned by both our shared currency and our free borders".
The First Minister told MSPs she will not "simply accept" a Scottish exit from the European Union.
Nicola Sturgeon said: "My position is very clear - I want to give effect to what Scotland voted for. I don't want us to be ripped out of the European Union against our will."
She added: "I am not prepared as First Minister simply to ignore how people in Scotland voted last week.
"I'm not prepared to shrug my shoulders and simply accept that a Tory government that we didn't even vote for here in Scotland can drag us out of the European Union against our will, and I think a majority of people here in Scotland agree with that position."