Figures out today have revealed GDP in Scotland grew at just 0.4 per cent in the last quarter, behind the UK rate of 0.7 per cent.
And for the past year, Scotland's economy grew at just a third of the rate of the UK's, 0.7 per cent compared to 2.1 per cent.
Shadow economy secretary Dean Lockhart said, considering the SNP had been in charge of the economy since 2007, it was now time for it to fully explain its failures.
He added the nationalists couldn't even blame Brexit on this occasion, as the statistics were gathered prior to the vote.
Scotland's chief statistician said while services and production grew north of the border between April and June, that was tempered by a fall in construction.
This is the latest report which confirms that in every year since the SNP came to power, the economy has either shrunk, or grown at a slower rate than the rest of Britain.
Scottish Conservative shadow economy secretary Dean Lockhart said:
"We welcome the fact that Scotland's economy has experienced some growth over the past three months.
"But we have to recognise that economic growth of 0.4 per cent simply isn't good enough when you compare that to the rest of the UK.
"The Scottish economy continues to massively under-perform in relation to the rest of Britain's, and that's entirely on the SNP's shoulders.
"These figures were gathered prior to the EU referendum, so the nationalists can't even blame Brexit.
"The Scottish Government has significant new tax and spending powers that will determine the size and shape of the Scottish budget going forward, not to mention spending levels on health, education and justice.
"As experts have noted, public sector spending now depends heavily on the performance of Scotland's economy, and if that continues to be worse than the UK's, services will undoubtedly suffer.
"Unfortunately, this is a Scottish Government not interested in the economy.
"Its one clear priority that transcends all others is separation at all and any cost, something the First Minister has herself admitted.
"As the SNP prepares for its conference, instead of stoking uncertainty with more independence threats, it should be thinking about how to address its decade-long failure of Scotland's economy."