NICOLA Sturgeon has said she “will not hesitate” to reform Scotland’s drug driving law if research proves recent changes have worked south of the border.

The First Minister gave the commitment after being accused of allowing Scotland to fall “behind the curve” by relying on out-dated legislation to prosecute drivers.

Prosecutors across the UK previously had to prove a person’s driving was “impaired” by drugs to secure a conviction.

But in March 2015 specific blood levels were introduced for 17 illegal and prescription drugs in England and Wales, and driving above the threshold became an automatic offence.

Those caught after a roadside swab test face a minimum 12-month driving ban, up to six months in prison, an unlimited fine and a criminal record.

Police have recorded a surge in arrests and a near doubling of conviction rates.

However in Scotland, the law remains based on proving impairment.

SNP MSP Stuart McMillan asked Ms Sturgeon if she would revisit the law on drug-driving after an evaluation of the English system later this year.

The First Minister said drug driving was “completely and utterly irresponsible”, and the government was committed to making roads safer “based on the evidence of what works”.

She said: “If the evidence shows that that has been successful and that lives can be saved, we would not hesitate to legislate here.”

Tory justice spokesman Douglas Ross said the evidence was already overwhelming.

He said: “We know that there has been a fourfold increase in the number of motorists charged with drug-driving and that conviction rates have risen from 52 to 95 per cent.

“Is that not the evidence that the First Minister needs? Why is Scotland behind the curve, compared with the rest of the United Kingdom, on this important issue?”

Ms Sturgeon replied: "We will wait for the evaluation of the drug-driving limits in England and Wales to inform our consideration of the best approach to the issue in Scotland and to see whether that development would help us to make our roads even safer. ”

Ms Sturgeon also defended her record after a new report flagged “major weaknesses” in education and said there “no specific area where able children in Scotland really excel”.

Tory leader Ruth Davidson said the SNP had “failed utterly” over 10 years in office and the findings were “particularly shameful” on attainment and science.

Labour’s Kezia Dugdale also blamed the SNP for “catastrophic failures".

Noting the report used two-year-old data, Ms Sturgeon insisted SNP reforms, including a £120m attainment fund, were narrowing the gap between rich and poor pupils.