A former SNP minister has been forced to issue a public apology after he sparked a furious row over the 1984 miners' strike.
SNP MSP Adam Ingram claimed that Lord Foulkes of Cumnock, then MP for Auchinleck in Ayrshire, had been "silent" over the workers plight.
But his comments provoked a staunch backlash from the Labour peer.
He wrote to Mr Ingram, and Holyrood's presiding officer Tricia Marwick, accusing the SNP politician of lying and demanding a swift apology.
He also produced a photograph from the time showing him taking part in a protest march in support of the miners' cause.
Last night, Mr Ingram admitted he had been wrong.
In a statement he said: "I welcome Lord Foulkes' correspondence, and am pleased to be informed that he was active in assisting the miners in Ayrshire, and therefore apologise for my remarks to the contrary."
However, he added: "My wider point is that support from the Labour leadership was not as forthcoming."
In the letter, Lord Foulkes wrote: "Your assertion is a lie and you must know it to be so. I was not at all silent during the strike, in fact quite the reverse."
He added: "I am deeply upset by your untrue assertion.
"While I am more than used to the banter of politics I take great exception to you lying to make party political capital and demand that you issue a public apology immediately or I will have to consider what further action to take."
Lord Foulkes also wrote that during the strike he supported the Ayrshire National Union of Miners.
"I joined them on the picket lines at Sorn, Barony, Highhouse and Killoch pits and at Hunterston Port, where coal was being imported to try to break the strike. Indeed the police surreptitiously followed mto the police station at Largs."