Nicola Sturgeon has said Boris Johnson is "frightened of democracy" on the question of another referendum on Scottish independence.
She quoted Robert Burns during an interview on the BBC's Andrew Marr Show, saying the Prime Minister's opposition to a second referendum reminded her of the poet's "timorous beastie".
It comes after the Sunday Times reported a series of opinion polls which found voters across the UK believe Scotland is likely to become independent within the next decade.
On Sunday, Ms Sturgeon was asked about the Prime Minister's suggestion there should be a 40-year gap between the last independence referendum and any future one.
She said: "It's Robert Burns' birthday tomorrow, our annual Burns Day.
"And when I hear Boris Johnson talk about this I bring to mind a Burns poem: 'Cowerin' timorous beastie, what a panic's in thy breastie'.
"He's frightened of democracy.
"The polls now show that a majority of people in Scotland now want independence."
Asked if she would hold an advisory "home-made Scottish referendum" if the SNP wins in the upcoming election, she said: "I want to have a legal referendum, that's what I'm going to seek the authority of the Scottish people for in May.
"And if they give me that authority that's what I intend to do."
Meanwhile, Scottish Conservatives leader Douglas Ross hit out at the SNP's publication of its "roadmap to a referendum" – an 11-point document which sets out how the party intends to take forward its plans for a second vote.
Mr Ross told Times Radio: "Why don't we have an 11-point plan to protect jobs in Scotland?
"Why don't we have an 11-point plan to ensure businesses get the support they need?
"Why don't we have an 11-point plan to rebuild our education system in Scotland?"
He added: "This is where the focus should be in Scotland right now, not fighting another independence referendum."
In response to the SNP's "roadmap", the UK Government said the issue of Scottish independence was settled "decisively" in 2014.
A spokeswoman said earlier: "Now more than ever, we should be pulling together to strengthen our United Kingdom, instead of trying to separate it."
The Sunday Times published the results of opinion polls in the four nations of the UK, which found a majority of voters thought Scotland was likely to be independent in the next 10 years.
In Scotland, the poll found 49% backed independence compared with 44% against – a margin of 52% to 48% if the undecideds are excluded.
In Northern Ireland, 47% still want to remain in the UK, with 42% in favour of a United Ireland and a significant proportion – 11% – undecided.
However, asked if they supported a referendum on a United Ireland within the next five years, 51% said yes compared with 44% who were against.
In Wales, where support for independence is traditionally weakest, 23% still backed leaving the UK while 31% supported a referendum.
Across all four nations, more voters expected Scotland to be out of the UK within 10 years than thought it would still remain.
The newspaper also reported that the UK Government's "Union policy implementation committee" had met and agreed a five-step programme.
These included a new campaign to promote the benefits of the Union ahead of the Scottish election, and to consider further devolution only later and only as part of wider reforms to the UK, according to the newspaper.
The Sunday Times also said that Oliver Lewis, a former Vote Leave campaigner, would lead new attempts to promote the Union.