The peer said people deserved a higher level of debate, urging the Yes campaign to "stamp out the culture of bullying and intimidation, that exists not just on the internet but in Scottish public life today and to seriously discuss the legitimate concerns people have about the option of Scottish independence".
Speaking during a Lords debate on Scotland's future, Lord McConnell focused his strongest remarks on supporters of the No campaign, saying they also needed to "raise their game".
He warned: "The lessons of 1979 and 1997 in Scotland are that divided campaigns do not succeed: united campaigns win."
The Labour peer explained it was "vital" for the Better Together campaign to win to "broaden its engagement with people outside of the traditional groups of political leaders who currently dominate the campaign and engage with those who through the 1980s and 1990s fought for Scottish Home Rule and for devolution and then participated in making it successful in the early years of the new Scottish Parliament".
He added most important was the "need to outline a positive vision for the future of Scotland inside the UK, not campaigning to protect the Union and the established order, but campaigning for what is the new order, a reformed UK with a new Scotland active and participating within it".
Liberal Democrat Lord Wallace of Tankerness warned Scotland would be undermined by independence. Tory peer Lord Laing argued it was not Scotland's victory at Bannockburn that had brought peace and security but the 1707 Act of Union.