Kenny MacAskill, Scotland’s justice minister, wants to bring Britain's drink-driving limits into line with most of Europe.
Mr MacAskill has told the transport minister, Geoff Hoon, that if Westminster fails to act, the power to cut the limit should be handed over to the Scottish Parliament.
Drink driving is blamed for 39 deaths and 170 serious injuries a year on Scotland's roads.
Mr MacAskill's move is the toughest stance yet taken by the Scottish Government. He also wants police forces to be given power to carry out random roadside breath tests on drivers.
He said: "This is not about constitutional niceties - it is a matter of making our roads safer.
"We are convinced a lower drink-drive limit would help to clarify the message that drinking and driving is unacceptable and, in the longer term, reduce the number of accidents."
LARSOA has consistently called on the government to reduce the drink drive limit. In January 2009, Alan Kennedy, vice-chair, said: "LARSOA believes that the only safe way to drive is with no known alcohol in the blood. Lowering the legal limit to 50mg would send out a clear, strong message that it is totally unacceptable to put lives at risk by driving under the influence of alcohol.”