Mr Johnson said the timing was wrong “when our European continent is being ravaged by the most vicious war in Europe since 1945 and when public services and the economy need to recover from the pandemic”.
He added: “How incredible that Labour should be so spiritually cowed that they have become nothing but the lapdogs and the enablers of the SNP.”
Ms Sturgeon’s administration is expected to publish legislation for a second referendum imminently, although the UK Government has said it would not allow a new vote to go ahead.
If the legislation is passed at Holyrood, it would be highly likely to be challenged in the Supreme Court, which most experts believe would rule that holding a referendum without the UK Government’s permission would be beyond the Scottish Parliament’s powers.
The Prime Minister claimed Ms Sturgeon’s plan to “turn off the taps and cap the wells” in the North Sea would leave the UK exposed to “continued blackmail from Vladimir Putin”.
Speaking in a city synonymous with the UK energy sector, he said Britain would continue to transition to a low-carbon future but added it was clear that there would be a “continuing role for oil and gas”.
“What is the policy of Labour and the SNP?” Mr Johnson said. “Turn the taps off now, cap the wells. What a disaster that would be. It means prices up, jobs lost and just when householders are feeling the pinch of high prices. And it means exposing the UK to continued blackmail from Putin.”
Mr Johnson also attacked the SNP’s “incredible” stance of advocating responding to “Putin’s sabre-rattling” by unilaterally giving up the UK’s nuclear deterrent.
Rona Mackay, an SNP MSP, claimed Mr Johnson’s speech was “tone deaf” and said: “It was an ill-conceived 15-minute charade laced with numerous personal insults and the same old tired bluster, but it contained not a single word of comfort for ordinary Scots suffering during this Tory cost of living crisis.”
Earlier, Rishi Sunak was accused of delivering an “insulting” speech to the conference which lasted just 137 seconds.
Delegates had been told to expect a “keynote address” from the Chancellor – but eyebrows were raised at a pre-recorded video address lasting less than two-and-a-half minutes.
