Scotland's business leaders have been accused of "an alarming lack of vision" after rejecting calls to make St Andrew's Day a public holiday.
The SCC said a public holiday could cost the economy up to £400m
The Scottish Chambers of Commerce (SCC) said more than 650 companies were opposed to the move and believed it would cost £400m in lost productivity.
Independent MSP Dennis Canavan wants Scots to be able to honour their patron saint on 30 November.
He urged the SCC to consider the economic benefits of the move.
Mr Canavan, the MSP for Falkirk West, has put forward a bill in the Scottish Parliament calling for the creation of a holiday on St Andrew's Day.
Holyrood's enterprise and culture committee gave its backing to the move, but MSPs narrowly voted to send the St Andrew's Day Bank Holiday (Scotland) Bill back to the committee for further examination.
SCC director Liz Cameron said any advantage of introducing a public holiday in terms of Scotland's tourist sector would have to be balanced against its economic impact.
She said: "It is important to remember that we are competing in a global market and it is essential that our businesses are given every opportunity to gain a competitive edge.
"Independent research has shown that this proposal could result in a loss of productivity totalling £400m."
The SCC has outlined its opposition to an additional bank holiday being created in a submission to the Scottish Executive.
Mr Canavan accused the SCC of an "alarming lack of vision" on the issue.
Dennis Canavan said Scots should be able to honour their patron saint
"They should look at what St Patrick's Day has done to promote the Irish economy nationally and internationally," he said.
"It would be preposterous to argue that a St Patrick's Day bank holiday does economic damage to Ireland, on the contrary it's a huge benefit to the Irish economy."
He added: "We should also remember that Scotland is at the bottom of the European league in terms of the number of public holidays.
"A St Andrew's Day bank holiday would not only give Scots an opportunity to celebrate their national identity, it would also be a great opportunity for many businesses, especially those connected with tourism, leisure, recreation and retail."
Tory enterprise spokesman Murdo Fraser agreed with the SCC's position and said the proposal would create additional cost without sufficient economic compensation.
He said the Tories advocated creating a St Andrew's Day holiday as a replacement for another day in the year.