Justice Secretary Kenny MacAskill has insisted it is still "appropriate" to ban drink drivers from the road for at least a year when a new lower limit comes in.

Holyrood formally approved measures to reduce the legal limit from 80mg to 50mg per 100ml of blood.

Mr MacAskill said the move would not only save lives but would bring Scotland into line with much of Europe, where lower limits are already in place.

The Justice Secretary told MSPs at Holyrood: "It's the right approach and will make Scotland's roads safer."

While other countries have a lower drink driving limit, the offence does not always attract an automatic driving ban, as it does in the UK.

Mr MacAskill said: "We are clear that the current automatic 12-month driving ban is appropriate at the current limit and will remain appropriate at the lower limit.

"There is strong evidence that drivers with a blood alcohol reading of between 50mg and 80mg are significantly impaired and an automatic ban is appropriate to deter people from drinking and driving."

While Holyrood has the power to alter the drink driving limit as a result of the Scotland Act 2012, Mr MacAskill it was a "missed opportunity" to devolve more responsibility over this area.

He said the Scottish Government wanted to allow the police to carry out random breath tests on motorists, as well as the power to set different limits for different groups, such as young and inexperienced drivers, and the ability to alter the punishments.

"It is right that this parliament should have the powers to set appropriate and proportionate penalties for drink driving," he argued.

He said there was a "persistent minority" of motorists "who despite repeated warnings put their lives and the lives of others at risk by getting behind the wheel after drinking alcohol".

Mr MacAskill added: "In 2012-13 4,730 people were convicted of drink and drunk driving offences in Scotland's courts.

"That may be a dramatic fall compared to the 8,145 people convicted of those offence in 2003-04 but too many people are still choosing to ignore the warnings and drink and drive.

"The consequences of drink driving can be tragic, drink driving costs lives. That is why it is right that we take action to reduce the risk on our roads."

He said an estimated 580 people were injured as a result of drink drive accidents in 2012, with an average of about 20 deaths a year over the last four years.

"Over the last four years an estimated one in 10 deaths on Scotland's roads involved drivers with a blood alcohol reading above the current limit," Mr MacAskill said.

"The current drink drive limit has had its day. If we look at the limits across Europe, it's only the UK and Malta which have a legal blood alcohol limit of 80mg of alcohol in every 100ml.

"Reducing the limit to a lower level of 50mg of alcohol per 100 ml will bring Scotland into line with most other European countries, it's the right approach and will make Scotland's roads safer."

Labour's Graeme Pearson said reducing the limit was "the right thing to do" and now was "the right time to do it".

The new, lower limit will come into effect on December 5, in time for the festive season.

Mr Pearson stressed the need for an education campaign about the change, saying: "It will be important that we further educate the community.

"There is a duty on this parliament and this Government to bring to their attention the impact of what could happen, particularly over the festive period."

He added: "I hope the Government does invest the necessary financial support to ensure an educational media campaign is launched."

While the Conservatives also backed the lower limit, Margaret Mitchell said the Scottish Government had failed to make clear that penalties for drink diving in Europe "are far less severe than those in the UK".

She said: "In France, for example, the penalties for a driver with a BAC (blood alcohol count) of between 50mg and 80mg usually consist of a fine with stiffer penalties for drivers who are well over the limit, including a more substantial fine and a licence suspension of up to three years."

Ms Mitchell also said the change in the law north of the border would mean "bizarrely drivers who live in England travelling in Scotland, who are over the 50mg but under the 80mg limit, potentially face severe penalties for a crime that has no statutory basis south of the border".

She added: "Had the positions been reversed, the SNP outrage would have been palpable."