Falkirk MP Eric Joyce is considering his future as a politician after admitting abusive behaviour at an airport.
Joyce was fined £1500 and ordered to pay compensation when he appeared at Edinburgh Sheriff Court.
He repeatedly hurled insults at baggage handlers in the city's airport on May 19 last year, and racially abused a black police officer.
The 53-year-old said he will now "reflect" on whether to continue at Westminster until the election next year.
"My instinct is to stay but I don't know how I will feel in a few days," he said outside court.
The former Labour MP has previously been fined over a brawl in the House of Commons two years ago - but has always insisted he will carry on sitting as an independent member.
"I am very embarrassed that this has happened," he said.
"My constituents have seen this before, so they might think other apologies are not meant, but they are."
Asked if he had a problem with alcohol, Joyce said: "I think I am well past that now."
He had been drinking on an evening flight from Heathrow to the Scottish capital last May, realising later that he left his phone on board, the court heard today.
He asked airport baggage handlers for help but became abusive when they asked for flight details.
Police officers became involved, but he continued to hurl insults.
Joyce began to "flail his arms" when one officer attempted to put him in handcuffs, and he continued to resist until he was restrained on the floor.
Sheriff Frank Crowe described his actions as a "deeply unfortunate, prolonged, drink-fuelled rant".
"At least you have taken this opportunity to apologise," the sheriff said.
As well as imposing a fine, the sheriff ordered Joyce to pay £100 compensation to airport staff and £50 to the police officer he racially insulted.
Defence lawyer Euan Gosney said: "A conviction of this nature will inevitably make a return to any form of public life difficult, if not impossible."
Joyce became an independent MP after he was expelled from the Labour Party following his conviction for assaulting politicians in a House of Commons bar in 2012.
The former Army major was fined £3000 and banned from pubs for three months following the brawl in the Strangers' Bar.