GLASGOW, Scotland -- Scotland's First Minister Alex Salmond has sought to calm fears that there would be repercussions against opponents of independence if the Yes campaign wins the upcoming referendum.

"The day after a Yes vote there will cease to be a No campaign and Yes campaign -- only Team Scotland. We will approach the success of Yes with magnanimity to all," Salmond said Saturday.

He spoke after former Scottish National Party deputy leader Jim Sillars told supporters there would be "a day of reckoning with BP and the banks" after the oil company and financial institutions voiced warnings this week over independence.

Saturday marked the biggest day of political campaigning Scotland has seen, including a peaceful march of 15,000 pro-unionists through Edinburgh and 35,000 Yes volunteers staging events across the country.

Polls suggest the race is extremely close ahead of Thursday's vote, which will determine whether Scotland remains part of the United Kingdom or becomes an independent country in 18 months.

The heads of several major retail chains warned Saturday that shoppers in Scotland would face higher prices if it becomes an independent country.

In a joint letter published in the Daily Record, the chiefs of Marks and Spencer, B&Q and Timpson said their experience in trading across national borders shows there is always an increase in red tape and costs.

Supermarket chiefs raised similar concerns earlier this week, and several large banks indicated they would have to move their legal headquarters out of Scotland into England if the Yes forces prevail.

Salmond had called these warnings scare tactics coordinated by Prime Minister David Cameron to frighten Scots away from independence.