The SNP must stop manoeuvring for a second independence referendum "that implies people were too stupid to get the answer right the first time," according to Scottish Secretary Alistair Carmichael.
The Liberal Democrat MP, who spearheaded the UK Government's defence of the UK, said the threat of Scottish nationalism and Ukip's threat of English nationalism point to "dangerous times" for the UK.
Speaking at the Scottish Lib Dem conference in Dunfermline, Mr Carmichael said new First Minister Nicola Sturgeon must use the powers she has to address inequality, invest in roads, reform the justice system and support the health service, particularly on mental health.
"Her commitment to people of Scotland will be measured by her willingness to act, not her manoeuvring for a second referendum that implies people were too stupid to get the answer right first time," he said.
"To those in the SNP who seek to keep their dream of independence alive by promoting the lie that we will not make good on our promises I say this: you are wrong, you know it, so stop it."
He added: "This is a dangerous time for our country. The long difficult years of austerity when people have seen their incomes squeezed as prices and other costs have gone up have produced fertile ground for parties offering easy answers.
"The forces of nationalism and populism have rarely been stronger - either the Scottish nationalism of the SNP or the English nationalism of Ukip.
"Telling people that all you need to do is draw a line on the map, pull up the draw bridge and all your problems will be solved - it is dangerous thinking and it is wrong."
Mr Carmichael also attacked the "dangerous and divisive" policies of Ukip.
"If Messrs Farage and Reckless start repatriating Poles and Greeks where will that leave the 1.4 million British citizens now living elsewhere in the European Union?" he said.
"An immigration debate that lacks a liberal voice, putting the positive case for a rational approach to a balanced system will be dangerous and divisive and ultimately will do harm to our economy here at home and our standing in the eyes of other countries overseas."
Lib Dem delegates later heard from a nationalist Scottish Green representative who argued that the Smith Commission on devolution is the next step to another independence referendum, perhaps in the next 10 years.
Substantial devolution will demonstrate Scotland's ability for self-governance and boost the case for another referendum, former Scottish Green head of media James Mackenzie told a fringe meeting organised by Reform Scotland.
But former Liberal Democrat MSP Margaret Mitchell argued too little devolution would also boost the case for another referendum.
Mr Mackenzie said: "Although I was an enthusiastic Yes voter, I don't want to spend my whole time talking about the constitution.
"I want to resolve it, to find a good place to be and a preference for what that was.
"I certainly don't want the next 10 years of devolution, or however long it is until we get another referendum, to be another debate about which powers we need."
The Smith Commission is "the next step to independence", he said.
"Scotland will be doing a lot more of its own self-governance, it will be building competence, demonstrating our ability to manage more powers responsibly and for me that feels like a basis for independence."
Ms Mitchell said: "A lowest common denominator offering won't be good enough.
"It's not going to be good enough to take small baby steps any more. This country wants settlement, stability, delivery on promises."
She added: "What if we fail? What if the next UK government fails to deliver?
"Then I believe we will be faced with a further referendum in the not-too-distant future, and the 45% will become the 55%."