First Minister Nicola Sturgeon has refused to rule out holding a wildcat independence referendum unauthorised by Downing Street.

The SNP leader will formally request for the powers to hold a vote - a section 30 order - from the UK Government next week but Downing Street said on Thursday it would reject any such request.

In an interview with STV News political editor Bernard Ponsonby, Sturgeon said there were "various options" open to her.

Sturgeon said it is the Scottish Government's "intention" to hold "a referendum on the same basis we had as the one in 2014".

When pressed on whether or not such a poll was an option if the UK Government refused to grant the powers to hold a vote, the First Minister said: "I will consider what options I have if I have to get to that point."

Scottish Labour have called on the SNP to remove "the threat" of such a poll.

Sturgeon said: "You can go round and round and round in this circle if you want. I am setting out what I have tried to do since June 23 last year, to set out a clear and logical path forward .

"Now, I have set out the timescale I think is reasonable. The Prime Minister has said what she has said. The Scottish Parliament next week will have its say.

"If the Scottish Parliament authorises me to seek a section 30 order I will formally seek section 30 order and then we will take it from there."

She added: "Just because the Prime Minister has said, a Tory Prime Minister with one MP in Scotland, she is going to defy the will of the democratically elected Scottish Parliament does not mean I have to immediately accept that it is a sustainable position.

"I am arguing a case here that derives from an election mandate for which there is majority support in the Scottish Parliament and I am going to continue to make that argument in the Scottish Parliament and to the wider Scottish public.

"I think we will find the Prime Minister is not in a position she can sustain and I would say to her, in all sincerity here in trying to be consensual, we seem to have a starting point of agreement that both of us think that now is not the right time for a referendum."

At a briefing to journalists on Friday, a Downing Street spokesman said: "It [calling a referendum] is a reserved power and the PM has been clear that now is not the right time."

When asked about a wildcat poll, he repeated five times: "Holding a referendum is a reserved matter."

Scottish Labour have called on the SNP to remove "the threat" of such a referendum off the table.

Ian Murray MP said: "The SNP must immediately withdraw the threat to impose an illegitimate and divisive referendum. Scotland is divided enough already without the Nationalists seeking to divide us even further.

"The SNP described the Edinburgh Agreement as the gold standard, because it established a legal basis for the 2014 referendum.

"It would be entirely unacceptable for a similar approach not to be taken if there ends up being another referendum. Credible governments and political parties do not impose referendums that do not stand up to legal scrutiny."

An unauthorised referendum has been held by the Catalan government who have been forbidden to hold a legal poll by the Spanish government.

Scottish Conservative deputy leader Jackson Carlaw said such a vote here would make the country a "laughing stock" across the globe.

He said: "The SNP's only reason for existing is to rip Scotland out of the UK.

"That's why the party refuses to rule out any means of achieving this, including a nonsense Catalan castanets consultative referendum.

"Such a process would make Scotland the laughing stock of the world.