A LABOUR MSP has been let off with a warning by Holyrood's presiding officer after he branded Nicola Sturgeon a "liar".

Neil Findlay withdrew the insult, which he shouted across the chamber during First Minister's Questions yesterday, after accepting that it was unparliamentary.

However, he offered no apology and pointed out that the First Minister had described Labour's policy of raising income tax as "dishonest" and a "con trick" and asked for those terms to substituted in place of liar.

The Herald: An apparently furious Tricia Marwick as she excluded James Kelly MSP from the Holyrood chamber

The half-hearted retraction apparently left Tricia Marwick unimpressed, with Holyrood's equivalent of the Speaker of the House at Westminster refusing to accept his suggestion that he had not known previously the term was unparliamentary. She said last night that she would consider what action to take in light of his comments.

A parliament spokeswoman confirmed this morning that she had written to the left wing MSP, a close ally to Jeremy Corbyn, and warned that she would take tougher action should he offend again.

She said: "The Presiding Officer has written to Mr Findlay making clear that any repeat of his behaviour and language in the Chamber yesterday will mean an automatic referral about his conduct to the Standards, Procedures and Public Appointments Committee."

Mr Findlay made the remark after Ms Sturgeon claimed Labour wanted to raise income tax for every worker earning over £11,000. The opposition insist their plan to raise around £500m to offset John Swinney's public spending cuts would see workers earning under £20,000 protected by a £100 rebate and those on modest salaries paying only marginally more with high earners bearing the brunt of the increase.

As MSPs debated yesterday whether to raise income tax or keep it the same as the rest of the UK, Mr Findlay said it was "utterly immoral" for highly paid politicians to "mislead" the low paid by telling them they would be worse off under the tax rise plan. He added: "Not only will they be financially better off, but their families will be better off as a result of improved services."

Nicola Sturgeon has said Labour want to shift the burden of Tory austerity onto the low paid while John Swinney, the deputy first minister, said Labour were targeting "low paid people busting a gut to make ends meet." The SNP has also criticised a lack of detail over how the rebate proposal would work in practice.

Mr Swinney's plan not to raise income tax were passed after being backed by Conservative and Green MSPs but opposed by Labour and Liberal Democrat members.