The party in Scotland is calling for the currency to be legally protected in England to stop it being rejected in shops and businesses south of the border.
Shadow Scottish secretary Alistair Carmichael told the BBC Scotland news website: "It is ironic that many shops and businesses in London have signs indicating that they will accept euros. Scots in England have no legal recourse whatsoever when their banknotes are refused, leading to embarrassment and irritation. This situation is the result of historic accident and it is now time to address it."
Carmichael has written to Bank of England governor Mervyn King to ask for a ruling on the status of Scottish notes. Scottish and Northern Irish notes are not legal tender, but shops can still accept them as payment.
Scottish notes are issued by the country's three largest private banks - the Bank of Scotland, the Royal Bank of Scotland and Clydesdale Bank.
The Scottish government's justice secretary Kenny MacAskill has defended licence fees for the new regime as "fair and reasonable".
The fees for the new personal and premises licences have been described by the Scottish Grocers' Federation as a "staggering increase" on what retailers are paying under the old system (OLN Jan 11). Retailers will incur costs of up to £2,000 for licence applications and up to £900 in annual fees, depending on the size of their shop. The changes are part of Scotland's new Licensing Act, which comes into force on Sept 1 2009.