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."