The Scottish Government would be "very confident" of defending plans to bring in plain packaging for cigarettes if there was a legal challenge from tobacco companies, the Public Health Minister said.

Michael Matheson insisted that introducing plain packs for cigarettes and other tobacco products was necessary to help Scotland "build a generation free from tobacco".

He was speaking after reports claimed the industry was ready to sue the Scottish Government for £500 million if plain packs are introduced north of the Border.

But anti-smoking campaigners at ASH Scotland warned any legal action by cigarette firms was "unlikely to succeed".

Last week MSPs unanimously backed a motion at Holyrood that would allow any future legislation on plain packaging that is brought in by the UK Government to apply north of the Border too.

Westminster is set to make a final decision on whether plain packaging should be introduced in the coming months, after an independent review is published.

But Scotland would still be able to press ahead and introduce the change, if Westminster opted not to go ahead with the move.

Mr Matheson said: "We would be very confident of defending any legal action from tobacco companies, having done so successfully on every previous occasion that they have taken legal action against the Scottish Government. We also note that Australia has had plain tobacco packaging in place for over a year."

He added: "To build a generation free from tobacco it is necessary to restrict the imagery and designs that could pull in another generation to use these addictive and lethal products."