Three police and crime commissioners have joined calls to lower the drink-drive limit in England and Wales to the same as Scotland.
The House of Lords will debate the issue on Friday after it was introduced by Lord Brooke of Alverthorpe as a Private Members' Bill.
North East PCCs Vera Baird, Ron Hogg and Barry Coppinger, for Northumbria, Durham and Cleveland, have written to Transport Secretary Patrick McLoughlin to express their support.
The limit in England and Wales is 80mg of alcohol per 100ml of blood, but in Scotland it is lower at 50mg, and that could cause confusion for people crossing the border from Northumberland, Ms Baird said.
"I'm adding my support to the many local residents calling for a lower drink-drive limit," she said.
"If we can get this into law now, I know that many lives will be saved in the weeks, months and years ahead.
"As the Northumbria force borders on to Scotland, many local residents could be abiding by the drink-drive limit in our region, but find themselves breaking the law in Scotland."
Lowering the limit in England and Wales in line with Scotland's would have saved around 25 lives last year, an RAC report released last month revealed.
Steve Gooding, director of the RAC Foundation, said despite a rapid increase in traffic growth, the number of people killed in drink-drive accidents had fallen dramatically, down 85% since 1979.
But more could be done.
He said: "It would be a poor argument to suggest we should cut the drink-drive limit just because everyone else has done it. But this report makes the case on robust data and sound analysis.
"Policy in this area hasn't moved for half a century but in the face of this evidence it increasingly falls on opponents of a limit reduction to defend the status quo, rather than asking those who support a cut to keep making their case."