Scottish Conservatives leader Ruth Davidson has set her sights on deposing "blundering" Labour as Scotland's main opposition as she attacked Kezia Dugdale's "weak" defence of the UK.

Several recent polls have shown the Conservatives are gaining on Labour in the race to be Holyrood's second biggest party amid the ongoing dominance of the SNP.

In a speech in Stirling, Ms Davidson will attempt to gain further ground by appealing to the two million people who voted No to independence to reject the SNP and the "chaotic" appeasement of nationalists within Labour and the Liberal Democrats.

But Labour said Ms Davidson cannot claim to be a supporter of the union after cheering on David Cameron's "despicable campaign that set England and Scotland against each other" in the general election.

Commenting ahead of her speech, Ms Davidson said: "If voters choose not to change the party of government in 11 weeks' time, they should consider changing the official opposition.

"In nine years, Labour hasn't landed a glove on the SNP - but we are committed to holding the Scottish Government to account, to keep it concentrated on the day job and away from referendum threats and false grievance.

"There are two million people who voted to keep Scotland a part of the UK, and in the past many of them have put their faith in Labour or the Liberal Democrats.

"But now they are looking for someone who has what it takes to be a real alternative to the SNP.

"People don't want to suffer five more years of Labour in official opposition - blundering about, punching wildly and never landing a blow.

"A Labour Party which still doesn't get it, and seems to blame the Scottish people for no longer voting for it.

"Both Labour and the Liberal Democrats say they are happy for candidates and future MSPs to campaign for separation - but I say they've got this one wrong.

"A vote for the Scottish Conservatives is a vote for the two million people the SNP is choosing to ignore.

"I call on the Labour Party leader (Kezia Dugdale) to reverse her chaotic position on the constitution.

"Her position right now is that Labour candidates are free to do as they wish - I think that's weak. This is too important and she needs to take control - a failure to do so will simply show that she is leading from behind."

A Labour spokesman said: "Ruth Davidson said nothing in the general election as David Cameron ran a despicable campaign that set England and Scotland against each other.

"She can't claim to be a supporter of the union now.

"However hard she tries to change the conversation she is just another Tory who has cheered on five years of Tory austerity."