Nicola Sturgeon has suggested the pro-independence movement has both democracy and time on their side in their attempts to get the UK Government to allow another Scottish referendum.

Scotland’s First Minister said that if Boris Johson is “playing a waiting game, I’ve probably got time on my side” because younger people are more likely to favour independence – a statement some have interpreted to mean awaiting the death of older voters.

In an interview with the Financial Times, Ms Sturgeon said it would be “pretty unthinkable” for the UK Government to block another vote on Scottish independence, something she wants to happen by 2023.

“I’ve got democracy on my side,” she is reported as saying.

“If they think it’s about playing a waiting game, I’ve probably got time on my side as well. You look at the demographics of the support for independence — well, I’m not sure that’s going to get you out of this conundrum.”

In her Programme for Government statement last month, Ms Sturgeon announced work was resuming to create a “detailed prospectus” in favour of independence.

The Prime Minister has repeatedly refused to countenance another referendum despite the nationalists arguing there has been a material change in circumstances since the 2014 vote because of Brexit, as well as the SNP and Greens both including the policy in their manifesto for the Holyrood election earlier this year.

Ms Sturgeon said that independence could only be achieved through a “legal, recognised constitutional process” but added: “If you’re saying that there is no legitimate, democratic, constitutional route for Scotland to choose independence, where does that leave us?”

“The union suddenly is no longer what it has always been: a voluntary, consensual union of nations.”

Responding to the comments about independence-backing demographics, Scottish Conservative MSP Murdo Fraser suggested it was an “erroneous assumption”.

He tweeted: “It’s also based on the erroneous assumption that people’s attitudes don’t change as they get older. We know that they do, and generally people become more risk-adverse, particularly when they have assets, savings, pensions and families.”

Chief executive of the Scotland in Union campaign group, Pamela Nash, said: “Nicola Sturgeon’s interview shows how utterly obsessed she is with constitutional division rather than being focused on her Government’s failings.

“And while she is less blunt, she is also making the same distasteful argument that her colleagues have repeatedly made about waiting for older Scots to die in the hope that this will deliver separation.

“The reality is that our younger generation are more interconnected than ever and want solutions for the future that will tackle challenges like climate change, not tired old constitutional arguments from the past.”