Media playback is unsupported on your device Media caption First minister's questions was dominated by Nicola Sturgeon's claim that Kezia Dugdale briefly changed her mind on a second referendum

Nicola Sturgeon has said she stands "100%" behind her claim that the Scottish Labour leader offered to drop opposition to an independence referendum.

Ms Sturgeon told a leaders' debate on Tuesday that Kezia Dugdale made the remark to her after the Brexit vote.

Ms Dugdale insists the allegation is a "categoric lie" and "gutter politics".

And she said it showed the first minister would "say anything to deflect from the SNP's appalling record".

The exchanges came on the final day of campaigning ahead of Thursday's general election.

The row was raised by Conservative leader Ruth Davidson at first minister's questions at Holyrood, when she asked Ms Sturgeon "why she believes that private conversations shouldn't stay private".

The first minister is said to have been alone in a room at her Bute House residence when she spoke to Ms Dugdale in a mobile phone conversation on the afternoon of the day after the EU referendum in June of last year.

The call is not thought to have been recorded, but some government special advisors were told about it afterwards because Ms Sturgeon believed Ms Dugdale's comments were significant.

Ms Sturgeon told Holyrood that details of the conversation had first been made public by Ms Dugdale in an interview with The Times newspaper on 23 February.

In the interview, Ms Dugdale said she had been "horrified" by the Brexit vote and had "pledged at that point to do everything I could, with the powers I had, to support Scotland having as strong a relationship with the rest of Europe as possible."

But Ms Sturgeon said Ms Dugdale's account of the telephone call had been "very selective".

Media playback is unsupported on your device Media caption Nicola Sturgeon first made the allegation during an STV debate on Tuesday

Ms Sturgeon said: "The part of that conversation that Kezia Dugdale didn't refer to was the part I spoke about last night, and stand by 100%."

The first minister went on to say: "If anybody reads what Labour and Kezia Dugdale were saying in public around that time, they will see the ring of truth about it.

"Labour themselves were saying that all options, including an independence referendum, were under consideration. That is the reality - it is on the record."

She also said that Ms Davidson had "hastily deleted" a tweet overnight in which the Conservative leader said she had recorded her own private conversation with the first minister in the wake of the Brexit vote.

Image copyright @kezdugdale

Ms Davidson responded by saying that everybody now knew not to have a private chat with the first minister because "if it suits her purposes, everybody will get to hear about it".

She added: "The truth is that we don't need the first minister to tell us what we already know, which is that the Labour Party can't be trusted to stand up to the SNP.

"And it is not just Kezia Dugdale, because Jeremy Corbyn is even worse. She says 'you can have your indyref', and he says 'absolutely fine'."

She also said only her party was clearly committed to saying "no to a second referendum, no to more uncertainty and no to the division it would cause our country".

Analysis by Brian Taylor, BBC Scotland political editor

Is the word "clype", I wonder, included in the lexicon of parliamentary terms? I only ask because it has featured en passant in the contention over the alleged chat between Nicola Sturgeon and Kezia Dugdale.

Actually, there is another reason for inquiring. Which is that the Presiding Officer, Ken Macintosh, seemed decidedly zealous in excluding certain words today.

He was not happy with the word "liar". He was leery about "untrue". Kezia Dugdale talked of "fake news" but seemed to get away with it.

The underlying topic? The claim by Nicola Sturgeon in a TV debate that she had a private chat with Ms Dugdale just after the EU Referendum last year in which the Labour leader suggested that she might be up for a plebiscite on independence, given the changed circumstances.

Read more from Brian

Analysis by Philip Sim, BBC Scotland political reporter

Both sides confirm that a conversation took place - they disagree about the content.

It appears there is no formal record of the conversation. Neither side admit to taking any notes. Where does that leave us?

The problem for Labour is that the claim has an air of believability. After all, Ms Dugdale did say publicly, in a notorious interview with the Fabian Society, that it was "not inconceivable" that she might back independence to keep Scotland in the EU.

She quickly clarified her position, and has worked hard on her pro-union credentials since - but the Conservatives have made endless hay with the idea that Ms Dugdale is weak on independence.

Five unanswered questions in the Sturgeon-Dugdale row

Ms Sturgeon had said during the STV debate on Tuesday evening that Ms Dugdale "thought Brexit changed everything and the Labour party could no longer go on opposing a second independence referendum".

But later in the debate, Ms Dugdale said: "The idea that I would do anything other than protect the United Kingdom and fight to remain in the UK is an absolute nonsense."

Ms Dugdale later tweeted: "Any suggestion that I ever said to Sturgeon that I'd change Labour's position on #indyref2 is a categoric lie + shows how desperate she is".

Speaking at FMQs, Ms Dugdale said the events of the previous 24 hours had shown that the first minister will "say anything" to deflect from her "appalling" record in government.

Calling on Ms Sturgeon to "focus on the day job", she asked why the number of unfilled posts for nurses and midwives in the Scottish NHS are at an all-time high.

Before she answered that question, Ms Sturgeon said: "I know what was said in that conversation, and so does she. And I am standing here in the chamber of the Scottish Parliament, and I am certain of what was said.

"And do you know what? There is nothing wrong whatsoever with Kezia Dugdale having changed her mind since then.

"But what is wrong is for Kezia Dugdale, having held that view, to suggest that people that still hold that view are somehow expressing something unthinkable."

Image copyright PA Image caption Mr Corbyn was cheered by supporters in Glasgow as he kicked off his final push for votes on Wednesday morning

Image copyright PA Image caption Ruth Davidson has accused Labour of being weak in its opposition to an independence referendum

She went on to say there were now 12,000 more people working in the NHS than when the government took office, and that there were more nurses, doctors and allied health professionals than ever before.

Ms Dugdale responded: "So there are enough nurses in the health service. That is the latest fib from the first minister" - a remark that saw her being rebuked by the presiding officer for unparliamentary language.

The Scottish Labour leader continued: "Yet more fake news from the first minister.

"Here's the reality - missed A&E targets, operations cancelled because of pressure on NHS staff and resources, and thousands of patients trapped in hospital when they are fit to go home.

"That should shame the first minister, except we know that nothing really does."

'Absolute nonsense'

The row was not mentioned by UK Labour leader Jeremy Corbyn when he was questioned by journalists ahead of his early-morning rally in Glasgow's Buchanan Street on Wednesday.

He said only that his priority was the election of a Labour government, and that he does not "see the urgency or the need for an independence referendum".

Meanwhile, Scottish Liberal Democrat leader Willie Rennie told activists in Fife that votes for his party would help to elect MPs that will stand strongly against independence and put the local community first.

Mr Rennie said: "In this election we have set out a clear and positive message that Scotland is best served when it is at the heart of the UK and the UK is at the heart of Europe.

"The SNP have been focused on only one thing and this election is our chance to tell them that another independence referendum is the last thing we need."