Douglas Ross has “contributed more than anyone else to the toxicity of relationships in the Scottish Parliament,” John Swinney has said.

The comments from the First Minister came after the outgoing Scottish Tory leader claimed the SNP would "lie through their teeth" to win votes.

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He told the Express: "They will lie through their back teeth to get support and we are seeing that, again.

"They will stop at nothing to get the support of local people in seats across the country.

"And as soon as the election is over, they will use every vote cast for them as an argument for independence.

"We need to stop that and the best way to stop that in key seats is uniting behind the Scottish Conservatives to beat the SNP."

Mr Swinney was asked about the comments while speaking to journalists at a campaign stop at the Scottish Power training station in Cumbernauld.

At first, the SNP leader said the remarks were “unworthy of a response.”

Asked again, he replied: “I think it tells us all we need to know about Douglas Ross.

“Douglas Ross, single-handedly, I think has contributed more than anyone else to the toxicity of relationships in the Scottish Parliament.

“And that's another comment to add to the list.”

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It is not the first time the two men have clashed over politics and the truth.

In May, Mr Ross was carpeted by Presiding Officer Alison Johnstone after he sarcastically referred to Mr Swinney as “honest John” during a fiery exchange on the SNP's position on new oil and gas licences. 

The SNP leader said Mr Ross was not “in a particularly strong position” to criticise the honesty of others.

Responding to Mr Swinney's comments on Mr Ross's "toxicity" a Scottish Tory spokesman said: "As Douglas pointed out, this election is a straight fight between the Scottish Conservatives and the SNP in key seats across the country.

"If voters unite behind us, they can end the SNP's independence obsession for good. 

"But a vote for any party other than the Scottish Conservatives - including Reform - or not voting at all, risks the SNP getting in by the back door in those seats. And we know John Swinney will use every single SNP MP elected to push for the break up of the UK."