An aide to the Labour leader at the Scottish Parliament has resigned in disgrace after calling the First Minister a “c***” at an awards ceremony.

Matthew Marr, chief press aide to Wendy Alexander, issued a grovelling apology for his behaviour at the Scottish Politician of the Year Awards last Thursday, which culminated in him screaming abuse at Alex Salmond before apparently ranting to bemused onlookers: “I hate the f***ing middle classes.”

As well as launching a verbal assault on a Nationalist politician sitting at his table and insulting a cloakroom attendant, Mr Marr is also said to have greeted a fellow guest with the question: “Is that your bird, then?”

Described by Labour colleagues last night as a “stupid wee boy”, Mr Marr, 29, whose baby-faced appearance is at odds with his behaviour, apologised for his conduct. In a statement he said: “I believe that when people make a mistake, they should be prepared to take responsibility for it.

“Anyone who knows me will know my behaviour the other night was entirely out of character. I would like to offer my sincere apologies to the First Minister for what I said and to anyone else who was offended by my behaviour.”

Although the event has been held for less than ten years, boorish and drunken behaviour is fast becoming a proud tradition at the political awards dinner, which is held at the prestigious Prestonfield Hotel, Edinburgh.

Mr Marr’s outburst comes three years after a drunken Mike Watson, a former Labour minister and peer, set fire to a pair of curtains after attending the event. He was jailed for 16 months.

Mr Marr had been in his £45,000-a-year post for less than two months. As Mr Salmond went up to collect the top award at the ceremony, Mr Marr loudly declared that the newly elected First Minister was a “c***”. Although Mr Salmond did not hear the remark, Jennifer Dempsie, one of his special advisers, who was seated at Mr Marr’s table, was said to have been deeply offended. She told friends that Mr Marr had spent the evening being obnoxious to her.

One guest said: “Politics is about the rough and tumble, so a bit of banter is fine. But to use a word that most people find deeply unacceptable, especially at a public event, was appalling.”

It was reported yesterday that Mr Marr had begun drinking at the event, in Edinburgh, about 7pm on Thursday and had continued until 1am. A spokesman for Mr Salmond said: “The First Minister regards the matter as closed.”

Although Ms Alexander initially ordered her inner circle to protect Mr Marr, a Labour insider said: “It was when she heard that he had also been rude to staff at the hotel that she realised it had gone too far.”

Ms Alexander said: “Matthew Marr has tendered his resignation and I have accepted it. His behaviour was out of character and he has apologised.”

The episode has raised questions about the judgment of the Scottish Labour leader, who selected Mr Marr for the job. His predecessor, Brian Lironi, resigned apparently after finding that Ms Alexander was “demanding”.

Mr Marr was also accused of haranguing the Nationalist MSP Christina McKelvie, a member of Holyrood’s standards committee. She said: “His conduct throughout the night, in particular to women, was inappropriate.”

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